War powers controversies in the 1980s and 1990s centered on how the United States used force abroad, not on how it governed itself at home. Constitutional arguments and processes were instruments in the contest between presidents and Congress over American grand strategy – in the 1980s, how to confront the Soviet Union after retreating from Southeast Asia, and in the 1990s, what military burdens the United States should bear once that rival collapsed.

Barely a decade after Congress enacted post-Vietnam checks on presidential war-making, those constraints began to fray. As part of President Reagan’s strategy to roll back and ultimately defeat the Soviet bloc, his team worked to loosen legal restraints on both overt and covert operations. Yet Congress still exerted political leverage over interventions, and even weakened statutory limits remained tools of influence. Strategy generally led and law followed, but legal rules and processes still exerted modest constraint on executive unilateralism.

When the Cold War ended, a bipolar world suddenly gave way to a unipolar one. Although the United States now faced no foreseeable threat from a peer rival, it inherited a Cold-War body of constitutional practice – often marked by executive unilateralism – that presidents had justified as essential to a high-stakes global struggle. In the 1991 Gulf crisis, the President asserted the power to wage a major land war against Iraq without Congress, yet he ultimately sought and received its approval. As grave dangers then receded throughout the 1990s, the Executive Branch still claimed vast powers to intervene in regional crises where vital U.S. interests were decidedly not at stake. However, in a decade defined by multilateral humanitarian missions and deeply divided public and congressional opinion about America’s global role, some administrations also began to sketch cautious boundaries around presidential power to use force. Those competing inclinations – assertion and restraint – continue to oscillate in executive-branch reasoning today.

The UN Security Council’s sudden revival after 1991 might have reopened dormant questions about how to reconcile multilateral decision-making with constitutional war powers. But American leaders were torn between sustaining U.S. dominance and deepening international governance. In practice, UN mandates loomed large in diplomacy but barely registered in constitutional debate.

Overall, in the 1980s and 1990s, war-powers fights were less about starting major wars than about how a superpower wielded armed force around the world. Presidents pushed unilateralism to support ambitious international agendas and Congress used process to maintain some grip on foreign policy – slowing and confining interventions, but rarely preventing them.

New Constitutional Balance for a New Grand Strategy

Aboard a flight to the 1980 Republican National Convention, Ronald Reagan was asked: “Why do you want to be president?” “To end the Cold War,” he replied.¹

Refusing to accept a stalemate, Reagan viewed the Cold War as an existential contest between the free world and Soviet Communism, in the constant shadow of nuclear apocalypse.² To win this contest against the implacable and expansionist “Evil Empire,” Reagan resolved to flex military power around the globe and increase support to anti-communist proxies in the Third World. A centerpiece of that strategy involved working with Congress to expand and modernize the U.S. armed forces, and Reagan presided over the country’s largest peacetime military build-up in history.³

The Reagan team believed that his grand strategic crusade would also need constitutional frameworks to match.⁴ Top officials and lawyers in the Administration argued that, after Vietnam and Watergate, Congress had tilted the balance of war powers too far in its own favor.⁵ Convinced these legal adjustments, especially when Democrats controlled Congress, could not accommodate Reagan’s strategic worldview, the Administration acted unilaterally in Lebanon, the Persian Gulf, Grenada, and Libya to reset the balance.

The Reagan Administration saw both its strategic ambitions and its constitutional philosophy as at odds with the 1973 War Powers Resolution and its embedded checks on presidential power. It could not always count on a reluctant Congress and a public still shaken by Vietnam to support its muscular foreign policy vision, especially when the President’s political allies lacked control of Congress. Across a wide range of issues, the Administration looked for ways to push back, sometimes very publicly, against what it viewed as congressional encroachment on executive power. Before Reagan’s first day in office, incoming White House Chief of Staff James Baker studied a memo from Dick Cheney, his counterpart in the Ford presidency, which urged the incoming administration to “restore power and auth[ority] to [the] exec[utive] Branch … [and show] strong [leadership]. Get rid of [the] War Powers Act – restore independent rights.”⁶ Over the next eight years, the Reagan Administration weakened the act, but never did kill it.

Lebanon offered an early proving ground for the Administration’s constitutional restoration effort. Hoping to stabilize the country and prevent deeper Soviet involvement, in 1982 Reagan deployed 800 Marines there as part of a multinational peacekeeping force, expecting the mission to last less than a month.⁷ In a letter notifying Congress “consistent with” (rather than “pursuant to”) the War Powers Resolution – a phrase chosen to denote that the Administration did not regard the law as binding, and one echoed by successive presidential administrations in War Powers Resolution notifications – Reagan wrote that “there is no intention or expectation” that the Marines see combat in Lebanon.⁸ As a legal matter, the Administration denied that American units were involved in actual or imminent “hostilities” that would trigger the War Powers Resolution’s sixty-day limit (as explained in Chapter 10, that law requires presidents to withdraw forces from such situations within two months unless Congress authorizes action). The word “hostilities” in the act, reasoned the Administration, meant intense combat operations. Sporadic or irregular violence in an area fell outside the law’s scope.⁹ Within weeks, though, violence in Lebanon spun out of control, and Reagan ordered the Marines to separate rival forces tearing apart the country. American personnel were now in the line of fire.

In the months that followed, those initial moves set off a rolling sequence of constitutional maneuvers and countermoves between the two branches. Determined to preserve what it viewed as essential presidential prerogatives, the Reagan Administration still maintained that the War Powers Resolution did not apply. The interbranch contest also highlighted the act’s lack of built-in enforcement mechanisms, and legislators struggled to assert their authority over whether Reagan’s unilateral operations should continue. Still, even a legally weakened Resolution framed the political debate, providing a statutory scheme for congressional critics of the intervention to begin rallying around.¹⁰ Both branches wielded legal arguments about war powers in a contest to control American foreign policy.

In June 1983, negotiations between the branches produced legislation requiring the President to obtain congressional approval for any significant increase in the number or role of American personnel in Lebanon.¹¹ Reagan signed the compromise law and pledged his intention to follow it. But he also stressed that Congress could not encroach upon certain presidential powers to use force when deemed necessary, without defining the scope of this power.¹² When Lebanese militias killed several U.S. Marines two months later, the shaken Administration worked to tamp down a barrage of congressional criticism by announcing that it was reassessing whether the War Powers Resolution had been triggered.¹³

By September 1983 – more than a year after the Marines first arrived – the Administration’s claim that American units were uninvolved in “hostilities” had lost credibility. As Congress considered new statutory limits on the deployment, officials worked to protect what they saw as important presidential authority for future crises. Reagan had no desire to expand U.S. operations in Lebanon or to commit to an open-ended presence, but he was equally wary of setting precedents that might weaken the President’s ability to deploy forces in future crises. That concern shaped how senior advisers presented the Administration’s position on Capitol Hill. Secretary of State George Shultz, a staunch defender of the Marine deployment, warned lawmakers that prolonged interbranch disputes over war powers created damaging uncertainty about American commitments. “[D]oubts about [American] staying power,” he argued, “would cause the aggressors to discount our presence – or to intensify their attacks, in hopes of hastening our departure.”¹⁴

Shultz’s warning reflected a recurring question since the early republic: Could American grand strategies that depended on credibly committing to use force – in this case, to deter war and to reassure allies of sustained American engagement around the world – be squared with a constitutional requirement for congressional approval? The Reagan Administration thought not, contending that the constitutional processes etched in the War Powers Resolution actually increased the likelihood of costly wars. Top officials were loath to countenance even minor legislative constraints on the Lebanon deployment, less because such limits would in fact have risked mission accomplishment than because any concessions risked establishing a precedent that Congress could restrict the Commander in Chief’s initiative in future crises. That obstinacy was bound up in a strategic worldview in which restoring and preserving American credibility – in the eyes of Soviet leaders, regional powers, and terrorist groups – was crucial.¹⁵

A head-on constitutional collision was averted when Administration officials and congressional leaders agreed on another compromise measure, authorizing the Marines to remain in Lebanon for up to eighteen months. Reagan Administration officials concluded that failing to reach a truce with Congress would narrow options for intervening in future crises. Reagan once again hailed a bargain. But upon signing the law, he emphasized the foreign policy dangers of “arbitrary and inflexible deadlines.” He also refused to acknowledge that he would be constitutionally bound by strict time limits, like the War Powers Resolution’s.¹⁶ These pronouncements had little practical impact: Reagan had no intention of keeping forces in Lebanon beyond eighteen months. Yet, anticipating future clashes with Congress, he refused to concede the President’s constitutional powers to do so.

That fragile compromise barely had time to settle. Less than two weeks after Reagan signed the measure, suicide bombers detonated truck bombs at two barracks housing U.S. and French personnel, killing 241 American servicemen – the U.S. military’s largest single-day death toll since the Vietnam War. The political fallout and the worsening strategic outlook in Lebanon soon led Reagan to withdraw U.S. forces, sealing the Lebanon mission’s reputation as a failure.

In the political reckoning that followed, Reagan accepted personal responsibility, but top Administration officials faulted Congress. Congressional restrictions, they argued, had made America’s intervention a paper tiger in adversaries’ eyes and thereby undermined Reagan’s strategy of restoring America’s global strength and credibility.¹⁷ The Administration’s attack on legislative restraints went beyond mere blame-shifting for the Lebanon retreat; it was a salvo in the continuing battles over war powers.

The Administration’s determination to reassert presidential initiative also surfaced in shorter, sharper interventions. In 1983, Reagan launched a successful invasion of the small Caribbean nation of Grenada, quickly toppling its Marxist-leaning junta. In 1986, he responded to Libyan-sponsored terror attacks by ordering air strikes on that country, achieving short-term tactical success against Libyan military targets and demonstrating U.S. long-range, precision-strike capabilities. Both operations were politically popular at home, and both were conducted without congressional authorization. In these brief cases, Reagan flexed American military muscle and the President’s constitutional muscle.

Near the end of Reagan’s second term, a very different regional conflict nonetheless tested many of the same constitutional boundaries. Since 1980, the Iran–Iraq War had turned into one of the century’s most harrowing conflicts, marked by the widespread use of chemical weapons, large-scale trench warfare with relentless human wave assaults, and the deliberate targeting of civilians. Strategically, victory by either side threatened to plunge the Middle East into deeper chaos and erode American influence in the region.¹⁸

When Iran attacked neutral oil shipping in the Persian Gulf to strangle Iraq’s economy, neighboring Kuwait appealed to both superpowers for protection. The Soviets agreed to escort Kuwaiti oil tankers under their flag, so the Reagan Administration faced a choice: allow Kuwaiti ships to sail under the American flag (and thereby commit to protect them) or risk expansion of Soviet clout in the region. With Cold War stakes in mind, Reagan chose the former.

Just as he had sent American troops to Lebanon, in 1987, Reagan ordered U.S. forces to safeguard free navigation in the Persian Gulf without first securing Congress’s assent – the largest naval convoy mission since World War II.¹⁹ This was akin to deploying tripwire forces across the globe – as discussed in Chapter 8, with major implications for if, when, and where the nation might fight wars – but this time at sea. For a time, Congress largely looked on. That changed abruptly in May 1987, when an Iraqi fighter jet accidentally fired on the USS Stark and killed several dozen sailors. Democrats, who controlled both houses of Congress, were alarmed, citing risks of escalation, another quagmire, and concerns about presidential unilateralism. Reagan’s top advisers were split over whether and how at that point to report the reflagging and naval escort operations to Congress according to the War Powers Resolution’s procedures. They agreed, however, that short-sighted congressional limits on presidential military action would undermine American security. An internal policy memo sent to Reagan and his senior aides warned that scaling back the operation would invigorate adversaries, raise doubts among allies, and leave the Executive Branch unable to conduct effective foreign policy with a Congress “emboldened to restrict [its] room for maneuver on a whole range of issues.”²⁰ These officials’ view of the President’s intervention had two self-reinforcing logics. First, the President had placed forces in harm’s way, and when they were in fact harmed, the President could exercise his commander-in-chief power to repel attacks, protect those forces, and vindicate American resolve. Second, threats to U.S. personnel provoked congressional questioning, which in turn raised doubts about American credibility, thereby justifying further presidential power.

Reagan and some top advisers went so far as to publicly and directly question the general constitutionality of the War Powers Resolution’s restrictions. Through various legal and political maneuvers, though, the Administration was able to avoid a showdown with Congress on that controversy. By Fall 1987, U.S. forces in the Gulf were routinely striking Iranian vessels and facilities, and an American naval vessel hit an Iranian mine. Yet the Administration denied that these clashes ever amounted to “hostilities” – the threshold that would trigger the Resolution’s sixty-day limit.²¹ It also treated these events as a series of discrete incidents, so even if the Resolution’s terms applied, the sixty-day clock would reset after every engagement.²² Later, when a large bloc of lawmakers sued to compel the President to abide by the sixty-day limit, a federal court dismissed the case as a political question unfit for judicial decision.²³ Applying and enforcing the War Powers Resolution remained a contest of wills between the political branches, with the judiciary sitting out the fight.

A sizable coalition in Congress tried pushing proposals to legally declare that the War Powers Resolution’s sixty-day limit had been and remained activated or to require a special congressional authorization for continued operations in the Gulf. Either of those might have obliged the Executive Branch to terminate the Gulf mission. In response, the President and top officials dug in, contending that such measures would unconstitutionally constrain the President’s power to use force and would, in their view, weaken American influence in the region. Reagan threatened to veto them.²⁴ Each violent Gulf encounter sparked new debates and restrictive proposals in Congress, and the Administration fended them off with a combination of veto threats, tough public talk about imperiled American interests, support from Republican allies, and small concessions like briefings to Congress. In doing so, the President avoided new legislation and, therefore, having to decide whether to override that statutory bar.

Congressional sponsors of these proposals were frustrated that Reagan’s stance upturned the War Powers Resolution’s core premise: that it would operate automatically, without lawmakers having to spend political capital to enforce it. Instead, Congress now found itself having to expend its limited leverage to pass measures that simply duplicated what the statute was supposed to accomplish – and to make matters worse, those measures would be vulnerable to presidential veto. This institutional imbalance only deepened after the Supreme Court’s 1983 decision in INS v. Chadha, which struck down the “legislative veto” device the Resolution relied upon: a concurrent resolution ordering troop withdrawal without needing presidential signature.²⁵ By invalidating that mechanism, Chadha effectively gutted one of the Resolution’s enforcement tools and left Congress able to compel withdrawal only through ordinary legislation subject to veto. Still, even in this weakened state, the Resolution served as a political rallying point, offering congressional critics a way to challenge Reagan’s approach on procedural grounds rather than by openly attacking the substance of an ongoing military engagement.²⁶

The constitutional battles over Reagan’s Persian Gulf operations were inseparable from the policy battles themselves, and they unfolded against a backdrop of sharp partisanship. One lesson of Lebanon was that the Executive enjoyed clear institutional advantages: It could act more quickly and decisively in law and foreign policy than the cumbersome Congress. Yet those advantages came with costs. The Administration had to spend considerable political capital to fend off successive legislative restrictions, which in turn made officials especially cautious about escalation. No clear evidence shows that congressional legal objections alone compelled the Administration to change course – so long as American casualties were minimal and escalation stayed below the scale of Lebanon – but proposals to loosen rules of engagement or widen the scope of Iranian targets threatened to draw renewed congressional resistance and heavier political costs.²⁷

By 1988, U.S. operations were suppressing Iranian threats, and an Iran–Iraq ceasefire eased interbranch tensions, ending any test of whether Congress would ever make the President back down. The Iranian threat to shipping through the Gulf subsided, and accordingly the U.S. intervention tapered off.

Congressional opponents never mustered support to cut off the President’s Gulf mission, but legal processes throughout the operation had been part of the frictional machinery of strategic choice. The War Powers Resolution proved less a legal brake than a political one – an argumentative framework that both branches invoked to claim legitimacy. Even as tensions in the Gulf eased, another confrontation over war powers was unfolding in a shadow war much closer to home

Waging Covert War in Nicaragua

In between Reagan’s Lebanon and Persian Gulf interventions, he waged a covert war in Latin America. The resulting Iran–Contra affair was more than a scandal of secrecy; it was a constitutional clash over Congress’s power to limit covert warfare. It also surfaced an extreme theory of presidential supremacy that, while beaten back in this case, would reemerge within the Executive Branch in the Global War on Terror two decades later.²⁸

During the early 1980s, the Reagan Administration supported the Contra rebels who were fighting to overthrow the Soviet-backed Nicaraguan government. Across the globe, the Executive Branch was supplying covert support to insurgencies and counterinsurgent forces to combat the Soviet empire and its proxies. For a President contemptuous of congressional interference and concerned about public war-weariness, such shadow operations were an attractive tool. And the covert campaign in Nicaragua was particularly alluring, because the threat lay right in the United States’ backyard.

The early phases of American intervention in Nicaragua entailed the CIA arming, training, advising, and funding of the Contras. The Administration unleashed propaganda campaigns against the Nicaraguan government and mined Nicaraguan harbors to disrupt commerce. These efforts were nominally covert: The U.S. government’s hand was unacknowledged and ostensibly hidden, and the actions were briefed to Congress in accordance with recent intelligence oversight statutes. In reality, CIA involvement was an open secret; the operations were too big to hide.

Administration efforts to topple the Nicaraguan government enjoyed little support on Capitol Hill or among the public. Congress answered with a steadily tightening series of “Boland Amendments” – the decade’s most explicit effort to check presidential adventurism. Named for House Intelligence Committee chairman Edward Boland, these riders to annual defense and intelligence appropriations bills prohibited U.S. military or paramilitary assistance to the Contras. They reflected lawmakers’ fears of another Vietnam-style entanglement, concerns about human rights abuses, and frustration with weak congressional oversight.

A cadre of White House and CIA officials, however, were determined to continue the covert war; rather than accept Congress’s limits, they pressed ahead, convinced that such restrictions threatened a vital regional struggle. In the mid-1980s, Reagan Administration officials sold arms to Iran in violation of arms export laws and diverted the proceeds to the Contras, contrary to the Boland Amendments.

Here, competing constitutional philosophies mapped onto competing theories of American power. To Reagan and his key advisers, unencumbered executive authority was not merely an institutional preference but a strategic worldview that saw presidential latitude as vital to credible U.S. leadership on the world stage. To congressional critics, by contrast, legislative checks embodied a belief that unchecked covert warfare endangered American security by inviting blowback and undermining democratic legitimacy.

The Administration’s policy caused a political and constitutional firestorm when it came to light in late 1986. Drawing partly on its implied Article I powers to oversee covert warfare, Congress established House and Senate select committees to jointly investigate what became known as the Iran–Contra affair. High-profile televised hearings featured testimony from Administration officials and CIA leadership, giving the public a rare view into the world of clandestine operations.

In late 1987, the joint Iran–Contra committee concluded that Reagan officials circumvented key congressional limits on covert war and violated both intelligence oversight requirements and the Boland Amendments, findings that were endorsed by most members in the Majority Report.²⁹ Abuses by Reagan officials, the report reasoned, undermined legislative checks on matters of national defense and suggested the need to strengthen oversight and accountability within both the Executive Branch and Congress. Ultimately, however, the report primarily served as a censure of a few bad apples. It lacked thorough constitutional analysis or deep critique of the functioning of checks and balances.³⁰ Congress largely ignored the report’s recommendations until the 1990s, when it finally implemented modest reforms to congressional notification requirements and oversight procedures.

The committee’s competing Minority Report was spearheaded by Dick Cheney, now a Republican congressman from Wyoming, and signed by seven other Republicans. Cheney, who had urged the incoming Reagan team to reassert executive power over warmaking, now took aim not at the Executive Branch but at Congress, urging for weaker legislative checks and pushing an audacious vision of presidential supremacy. While the report acknowledged technical illegalities and lapses in judgment by executive branch officials, it portrayed the Administration as making good-faith efforts – obstructed by Congress – to protect American interests.³¹ This counter-narrative aligned with an emerging conservative legal vision that concentrated executive branch power in the unitary President. That philosophy, also promoted by top Reagan Justice Department officials, blended originalist constitutional arguments with a campaign to roll back post-Watergate congressional checks, thereby helping consolidate presidential control across both foreign and domestic policy.³²

In the Minority Report’s view, Congress, not the Executive, had overstepped its constitutional role. As a policy matter, the minority urged Congress to refrain from imposing restrictions on the Executive Branch’s agility in conducting foreign policy, particularly in national defense. But the implications were more profound than a call for light-touch congressional oversight and regulation on matters of war and national security. The dissenting committee members hinted that on many dimensions of presidential foreign policy powers – including some uses of armed force – Congress might lack the constitutional power to intrude at all.³³

First, in a familiar analytical move discussed in Chapter 10, the Minority Report claimed that the President’s broad powers to use armed force and to engage in covert intelligence activities also extended to covert wars. Second, it implied that some forms of covert presidential warfare might be above the constitutional reach of congressional or judicial checks. Recall Justice Jackson’s framework from the Steel Seizure Case, which explained that the President’s authority is greatest when he acts pursuant to congressional authorization, and lowest when he acts contrary to congressional will. While Jackson left open the possibility that the President might lawfully contravene a statute that intrudes on his exclusive constitutional domain, he almost certainly viewed that exemption as a very narrow one. The Minority Report, in contrast, hinted at a broad exemption when it came to national security matters and offered no clear limits on that exemption’s scope. It wrote that historical practice “leaves little, if any, doubt that the President was expected to have the primary role of conducting the foreign policy of the United States,” and therefore if congressional restrictions “interfere with core presidential foreign policy functions, they should be struck down.”³⁴

As to Reagan’s covert war in Nicaragua, the joint committee minority was clearer: some of the Executive Branch’s activities covered by the Boland Amendments “were constitutionally protected against limitation by Congress,” and “[t]he executive was not bound to follow an unconstitutional effort to limit the President’s powers.”³⁵ The Reagan Administration was making similar arguments to Congress. While Reagan had not called the Boland Amendments unconstitutional when he signed them, his top lawyers raised constitutional objections to other proposed legislative checks on covert operations abroad, arguing that Congress could not interfere with the President’s freedom to conduct them.³⁶ Taken to its logical extreme, that argument might limit Congress’s power to constrain presidential powers in all wars, covert or overt.

That view of expansive presidential powers was not embraced by the Iran–Contra committee majorities. But, two decades later, Cheney – the congressional Minority Report’s chief signatory – would be Vice President when the United States was attacked by al Qaeda in September 2001. In the aftermath of those attacks, the Executive Branch would adopt even bolder versions of war powers formulas embedded in that report. Those arguments would lie mostly dormant in the meantime, resurfacing only after a relatively peaceful interlude, as the Berlin Wall’s fall in 1989 ushered in a close to the Cold War. During those quieter years – what seemed to some to be the “end of history” – the Minority Report’s fervent call for a supreme executive empowered to confront grave threats seemed far less urgent.

War Powers for Preserving Global Order

President George H.W. Bush called it a “New World Order.”³⁷ The end of the 1980s marked the close of the Cold War, as the Soviet Union buckled under economic and political strain. The Soviet Union’s dissolution in 1991 and the presence of the United States as the only superpower left standing fueled widespread optimism that global institutions, particularly the UN Security Council, could finally function as originally envisioned. There was still the question, nonetheless, whether the United States would energetically uphold this reimagined global legal and security system. The new order faced its first major test in the Persian Gulf. In the course of that trial, the UN Security Council – which both elected branches helped erect after World War II – played a major role in prewar American diplomacy to forge a multilateral coalition. Yet that UN revival mattered less than one might expect to the constitutional dialogue between the branches.

On August 2, 1990, Iraqi forces rolled across the border into Kuwait. Within a week, Iraq had conquered its tiny Persian Gulf neighbor, with which it long disputed territorial claims. In response, President Bush unilaterally dispatched half a million troops to oil-rich Saudi Arabia to deter further Iraqi aggression. The Bush Administration worked in parallel through the UN Security Council to build a broad international coalition and impose escalating economic sanctions on Iraq, demanding that Saddam Hussein immediately and unconditionally withdraw from Kuwait. Simultaneously, the Administration readied plans to go on the military offensive if Iraq refused to comply. In November, the UN Security Council set a January 15, 1991, deadline for Iraq to withdraw, authorizing UN member states to use any necessary military force after that date to achieve this outcome and restore peace and security.³⁸

For the United Nations, this marked a turning point. Throughout most of its existence, the Security Council’s power to authorize military action had sat inert. For forty years, the United States and Soviet Union approached nearly every crisis through a zero-sum, Cold War lens: Any Security Council action that appeared to favor one superpower was presumed to disadvantage the other. As a result, almost any proposed resolution authorizing force, save for occasional peacekeeping missions to monitor ceasefires, faced almost certain veto by one of them. The Cold War’s end removed that zero-sum logic from Council deliberations and enabled it, for the first time since the Korean War, to authorize major armed interventions.

Meanwhile, top administration lawyers had advised Bush that he had constitutional power to move from the defensive military buildup to offensive action without congressional authorization – an action that entailed overwhelming force and stood in contrast to Reagan’s more limited missions in Lebanon and the Persian Gulf. The military planned for possibly tens of thousands of American casualties.³⁹ Still, when Bush asked, the Deputy Attorney General by his own later account replied: “Mr. President, there’s no doubt that you have the authority to launch an attack.” The boldest argument was that the President had constitutional power, independent of Congress, to use even large-scale military force to protect U.S. interests. Another argument was that having put U.S. troops along Saudi Arabia’s border with Iraq, the President could act militarily to protect them; the President used one military power (to station troops abroad) in a way that justified another (to defend them).⁴⁰

Much of Congress disagreed. In the months leading up to war, the Senate held a series of high-profile hearings to debate Persian Gulf policy options, the U.S. role in enforcing international order, and constitutional war powers. Lawmakers from both parties demanded that the President secure congressional authorization before going on the offensive. “No one denies,” lectured Democratic Senator Edward Kennedy at the Armed Services Committee hearing, “that President Bush has inherent power to respond to an attack by Iraq on American forces or to deal with other legitimate provocations. But the Constitution is crystal clear that he does not have the authority to go to war in the circumstances that prevail at the present in the Persian Gulf.”⁴¹

Some key lawmakers believed that a formal war declaration, not a resolution authorizing the President to act at his discretion, was the appropriate mechanism.⁴² They bristled when Dick Cheney, now Secretary of Defense, brusquely told them that the President did not need their permission.⁴³ While the President sought maximum flexibility, Congress sought to preserve its primacy in decisions of war and peace. No doubt this was as much a political fight as a constitutional one: The country was split over whether a war was worth the cost, and public and congressional debates about war were still shaped by the lingering national trauma of Vietnam.

Frustrated by the Administration’s stance, a large group of congressmembers sued to block the President from launching offensive military action against Iraq without congressional authorization. The federal district court rejected the Administration’s argument that the issue was committed solely to the political branches, but it nonetheless dismissed the case as unripe, since Congress had not spoken as a whole and the President had not firmly committed to war.⁴⁴ As in many such cases, the court sidestepped – while leaving the door open if Congress acted more decisively.

Though he denied any constitutional obligation, in the end Bush went to Congress for a force resolution to enforce the UN’s Iraq mandates. After intense and extended debate, Congress narrowly approved the resolution – 52-47 in the Senate and 250-183 in the House – delivering Bush a victory just one day before the UN’s January 15 deadline for Iraq to withdraw from Kuwait. Privately, though, Bush had resolved to act with or without congressional backing. As he wrote in his journal, “In truth, even had Congress not passed the resolutions I would have acted and ordered our troops into combat.”⁴⁵ Bush’s approach formed a legal template that later presidents would employ, one that maximized political legitimacy without surrendering discretion.

On January 16, Bush ordered the launch of Operation Desert Storm, a multinational campaign that routed the Iraqi military. Within a week – much faster and with much less American bloodshed than many expected – the coalition compelled Saddam’s surrender.

In many respects, the series of constitutional moves extended some familiar patterns. First, while over the course of American history, the Executive Branch had generally asserted broader and broader presidential power to use military force, no president before the 1991 Iraq War – with the single exception of Truman in Korea – had waged a major ground war without express legislative authorization. No president has done so since then, either. Like President Johnson and the Vietnam War, Bush sought congressional authorization not because he thought it was constitutionally necessary, but because he wanted to strengthen his political and legal standing. Regardless, both Johnson and Bush got Congress’s approval before waging large-scale war.

Like the Gulf of Tonkin Resolution before it, Congress’s Iraq war resolution delegated to the President the ultimate choice of whether to wage war. Congress gave the President an option to wage war to enforce UN Security Council demands on Iraq, even if it seemed quite clear that Bush would take that step. Despite congressional rhetoric denying that it was giving the President a “blank check,” any concern about such a delegation of power was eclipsed by concerns in Congress about preserving its basic constitutional place in making war. The chosen means by which Congress exercised a role seemed far secondary to whether it exercised a role at all.

Moreover, while Congress asserted its prerogatives and voted on the 1991 Iraq war, it did so only after the President had again created what Hamilton termed an “antecedent state of things.” Based on his well-established Article II powers to command the military and conduct diplomacy, Bush had already sent hundreds of thousands of troops to the region, threatened Iraq with force, and obtained UN approval for a war, thereby skewing Congress’s deliberations and its political freedom of action. As Senator John Kerry griped at the time, “Are we supposed to go to war simply because one man – the President – makes a series of unilateral decisions that put us in a box – a box that makes that war, to a greater degree, inevitable?”⁴⁶ Kerry was identifying what Hamilton and Madison noted 200 years earlier: A narrow focus on the ultimate decision to make war can overlook the prior moves on paths toward or away from conflict.

As in past conflicts, interbranch agreement that the President could make war did not ensure agreement about how that war should end. Congress authorized the President to use force in implementing UN Security Council resolutions, but it gave him total leeway in how to achieve those goals. After chasing the Iraqi military back across Kuwait’s borders, for example, Bush could have ordered U.S. troops to roll into Baghdad and topple Saddam’s government. He declined to do so not because Congress’s war authorization limited his discretion but to preserve the international coalition and American public support. This loosely bound feature of the 1991 war authorization would reappear a decade later in another Iraq war resolution, but with far greater consequences.

Throughout all of this, the UN Security Council’s approval was scarcely a consideration in constitutional debates among political leaders. This was a constitutional dog that did not bark – a perhaps surprising development for those who had celebrated the idea of a new global order rooted in international law over brute might.

The 1991 Iraq war was the first U.S. war since Korea that was waged with UN Security Council backing. As noted in Chapter 8, Truman waged the Korean War under a UN banner, and his Administration argued that a credible and effective UN Security Council was sufficiently important to American interests that the President was empowered to use force in upholding it.⁴⁷ The Soviet Union was boycotting the Council at the time, so U.S.-backed resolutions sailed through. The UN Security Council answered the United States’ call, not the other way around.

One might have expected that in waking the UN Security Council from its Cold War slumber, the Iraq War would revive dormant constitutional questions from the UN’s Founding about how international governance and constitutional war powers meshed. Recall from Chapter 7 that post–World War II debates over the proposed UN Charter struggled to reconcile a responsive Security Council with cumbersome requirements for case-by-case congressional approval. In 1945, leaders in both elected branches believed that the new international governance system depended on the President possessing the authority to back it up. Most of them agreed that the President’s license to use arms would have to rest either on the President’s own constitutional powers or on Congress’s exercise of its war powers. To bridge that gap, they proposed that special agreements could – with congressional approval – allow the President to loan the UN some standby American forces. Many UN backers in 1945 also believed that Security Council interventions would be confined to “police actions.” Unlike war, police actions – shorter and more contained – would not require congressional approval. American political leaders did not resolve the question of how the Constitution would apply to a major, UN-sanctioned war that still gave Congress time to deliberate. The 1991 Iraq War exposed this unsettled issue, but it didn’t firmly settle it.

Some prominent legal scholars argued during the Iraq crisis that a UN Security Council mandate could substitute for congressional authorization.⁴⁸ Few Iraq war advocates in the Executive Branch or Congress, however, embraced that view. The President’s team stressed only the diplomatic value, not the constitutional value, of UN approval. When this issue arose in congressional hearings, war skeptics criticized the President, with Senator Kennedy blaring: “I think all of the American families have to be enormously distressed to find out that this authority about whether their children are going to go to war comes from some United Nations resolution rather than the Congress of the United States.”⁴⁹

Several factors help explain why UN Security Council resolutions carried little constitutional weight for the Bush Administration or its congressional allies in Congress. First, the Executive Branch could already rely on abundant Cold War precedent for broad presidential powers, and likely wished to avoid implying that if UN resolutions authorized action, they might also compel it. Second, domestic opinion was deeply split over a U.S. role in policing the world. Members of Congress worried that leaning too heavily on UN legitimacy in this instance would create a new, unwanted obligation to enforce international order wherever the Security Council pointed next. Democrat Joe Biden, for example, argued in a Senate hearing that many nations seemed content with standing aside while the United States shouldered the burden of the war. “That is not a New World order I am prepared to sign on to,” he warned.⁵⁰

There is a constitutional through-line here, going back to post–World War I debates over the League of Nations: even American political leaders who strongly supported collective security arrangements seldom claimed that a treaty or international body could override constitutional constraints on making war, whether by augmenting the President’s power to make war or by diminishing Congress’s. That pattern coincides with a general American approach to law, in which the Constitution always prevails over international obligations. At most, the Executive Branch pointed to Senate-approved treaties – like the UN Charter and mutual defense pacts – as evidence of interbranch consensus that certain military actions served vital national interests already within the President’s power to defend. Invoking these treaties also shored up political support for making war. For constitutional purposes, all the same, the President would rely almost exclusively on his own expansive Article II powers, Congress’s exercise of its Article I powers, or some combination of both.

In the case of Iraq, the Executive Branch claimed presidential power to make war, Congress pushed back by asserting its sole power to do so, and the President ultimately chose to obtain congressional approval – without conceding he needed it. But this was a major war fought for major U.S. national interests. With the Cold War over and the Gulf War won, presidents next faced a subtler question: Could the same constitutional powers once used to deter and contain America’s peer rival justify interventions where no vital interest was at stake? In the years that followed, Bush and his successors engaged in a series of such missions, leading to a more bounded executive branch formula of presidential power – at least with respect to the magnitude of military action.

Humanitarian Intervention and War Powers

As the lone superpower in the 1990s, the United States faced questions not only about maintaining international security but also about preventing humanitarian disasters. The nation and political leaders were still split over whether the United States should bank a “peace dividend” and draw down its overseas commitments or instead embrace the burden of underwriting global order. As successive presidents inclined toward the latter role, the Executive Branch refined a constitutional framework that, though bounded in theory, justified the President’s broad authority across an ever-widening spectrum of foreign engagements in which U.S. security interests were not directly threatened. United Nations Security Council mandates often supported these humanitarian missions. Still, the UN continued to play little role in American constitutional debates, as the Somalia and Haiti interventions would show.

In 1991, Somalia collapsed into a failed state, as severe drought and warring factions produced a humanitarian catastrophe. In response, the UN Security Council in 1992 created an aid mission with authority to use military means to carry it out, and President Bush sent 28,000 troops to lead a multinational UN relief effort.⁵¹ When armed Somali gangs stepped up attacks on UN peacekeepers, Bush’s successor, Bill Clinton, unilaterally expanded the aid mission into a combat one by tasking U.S. forces with capturing the ruling warlords. In October 1993, militias shot down two U.S. Blackhawk helicopters, killing eighteen American soldiers. Under public and congressional pressure, Clinton announced the withdrawal of American personnel by Spring 1994.

At the same time as the Somalia deployment unfolded, another crisis was beginning on the other side of the globe. Haitian military officers deposed the country’s president in 1991, sparking political turmoil that caused a humanitarian crisis. In 1993, the UN Security Council imposed economic sanctions and called on UN member states to enforce them as a means of pressuring the junta to restore civilian rule. Those efforts failed. When U.S. diplomats won UN approval in 1994 for a multinational coalition under American command to restore Haiti’s civilian leaders, the Executive Branch began invasion planning. Days before the scheduled assault, Clinton’s envoys negotiated a return to civilian rule in Haiti. The President sent 20,000 U.S. peacekeepers to serve alongside a multinational force to stabilize the country.

In both Somalia and Haiti, executive branch lawyers asserted that the President could send military forces abroad if the President thought that doing so was in the national interest, including for humanitarian reasons. United Nations Security Council diplomacy was important to both missions, but in neither was it important in constitutional analysis or debates.

The Bush Justice Department stressed in its legal advice on the Somalia mission that the President could reasonably view famine prevention as a sufficient national interest to justify presidential military action. It also noted that the President could regard maintaining the UN Security Council’s credibility and protecting its missions – promoting a New World Order – as adequate reason.⁵² The Department’s opinion recalled the Truman Administration’s rationale for the 1950 Korea intervention, which treated bolstering the UN as one reason, among others, for acting. In 1950, the UN Security Council’s mandate did not itself satisfy any constitutional requirement; it simply supplied a fact supporting the Executive’s claim that the President was acting to secure American priorities. Both elected branches at that time regarded sustaining the UN as vital to national interests (the Senate had only recently voted to ratify the UN Charter). By contrast, the 1992 analysis cast the need to maintain the UN only as a reasonable presidential judgment, with scarcely any reference to Congress.

In the case of Haiti, members of Congress raised familiar protests to presidential intervention without legislative approval. When Senate Republican leaders asked the Justice Department for its legal advice on the President’s planned deployment, the Department cited several factors supporting the President’s authority. Most significantly, the Justice Department claimed that the “nature, scope, and duration” of the planned mission was not a “war” as meant in the Constitution’s Declare War Clause.⁵³ Because the operation did not, in the President’s view, entail risks of major or prolonged combat or grave danger to American personnel, Congress’s approval was constitutionally unnecessary.

By that logic, the inverse was presumably also true: If the nature, scope, and duration of a planned intervention did rise to the level of war, Congress’s approval would be constitutionally required. Yet the Executive Branch had not – and still has not – been consistent on that limiting principle. Just a few years before the Haiti operation, President Bush and his top Justice Department officials had publicly taken the position that legislative authorization for major war against Iraq was unnecessary, though career Justice Department lawyers apparently were skeptical of such an expansive interpretation of the President’s powers and Bush ultimately went to Congress anyway and received its approval.⁵⁴ But the Clinton Administration’s concession had precursors, too. As explained in Chapter 10, Assistant Attorney General William Rehnquist had acknowledged a similar, if vaguer, limit in his constitutional analysis of the Vietnam War and its extension into Cambodia. In his May 1970 opinion, he argued that hostilities reaching a “certain scale” must be brought to Congress, called the Korean conflict “the high water mark of executive action without express congressional approval,” and concluded that Congress later acquiesced in Truman’s actions by “repeatedly vot[ing] authorizations and appropriations to arm and equip the American troops.”⁵⁵ Perhaps trying to mitigate congressional dissent, and sensing few grave dangers for which the President might need to use large-scale force unilaterally, the Clinton Administration went public with its concession that presidential power to use force is limited to missions short of war – as defined by some still-vague combination of the anticipated nature, scope, and duration of military operations.⁵⁶

In concluding that the Haiti intervention was not “war” in a constitutional sense, the Justice Department emphasized that the 20,000 U.S. military personnel were being sent with the consent of Haiti’s legitimate government and in noncombat roles. The Department alluded only in a short footnote to the UN Security Council mandate, noting there could be “no question but that the deployment is lawful as a matter of international law.”⁵⁷ As in the Gulf War case, stressing the UN’s blessing above Congress’s would likely have backfired politically with a public still divided over whether the United States should be the world’s policeman. In fact, throughout this period, Republican members of Congress periodically pushed to bar the President from placing any U.S. troops under UN command. Even if Clinton had no plans to do so, the Justice Department opined that such restrictions would unconstitutionally intrude on the President’s powers as commander in chief, and the measures failed.⁵⁸ Still, the disputes suggested that for some factions on Capitol Hill, a UN banner might be a factor cutting against, not in favor of, presidential power to use force.

Although the President had wielded broad power to intervene in Somalia and Haiti to protect vulnerable populations, Congress did not simply recede to the background. After the October 1993 debacle in Somalia, it pressured the President to withdraw American personnel and then reinforced that demand by blocking funding for continued operations.⁵⁹ In Haiti, Clinton also had to spend political capital fending off threats of congressional restrictions. He later acknowledged that he “had to consider the consequences of any action that could make it even harder to get congressional support for sending American troops” to other crisis zones, “where we had far greater interests at stake.”⁶⁰

In the Somalia and Haiti cases, international legality – specifically, UN Security Council backing – was treated as a small plus-factor in constitutional analysis. It was helpful, but certainly not sufficient. But was it necessary? What if a humanitarian mission lacked such approval? Would that undercut claims of presidential power? The Kosovo campaign was a test case for this question. It turned out that the absence of justification under international law barely registered in the constitutional analysis at all.

Thousands of miles from Somalia and Haiti, Yugoslavia was splitting apart. At first the UN Security Council blessed military action – in which the United States participated – to contain brutal conflict in seceding provinces. But by the late 1990s, the Council was divided over the Balkan wars. In 1999, Russia aligned itself with the Serbs in rump Yugoslavia, who were waging a savage ethnic cleansing campaign against the breakaway Kosovo region. When the United States and West European allies urged the UN Security Council to compel the Yugoslav leadership to relent, Russia and others stood in the way. The New World Order had barely arrived, and it was already crumbling.

In March 1999, without approval from Congress or the UN Security Council, the Clinton Administration ordered U.S. forces to lead a major NATO air assault against Yugoslavia, drawing on constitutional arguments for humanitarian operations. What was expected to be a brief campaign turned into seventy-eight days of relentless bombing before leaders in Belgrade backed down.

The Clinton Administration did not publicly elaborate on the constitutional grounds for its initial intervention, but it later claimed that Congress approved the operations by voting to fund it.⁶¹ A group of lawmakers challenged this in court, charging that the military campaign violated the Constitution and the War Powers Resolution, which states that congressional approval should not be inferred from Congress’s funding measures. However, an appeals court tossed out the case for the legislators’ lack of standing.⁶² Once more, the courts refrained from defining the boundaries of presidential powers to use force, although the judges in the case split over whether courts should ever rule on such matters in the future.

The Administration also never offered an international law rationale for the intervention, because it did not have one. The President and top officials emphasized that NATO countries were acting collectively and for just cause, but there was no solid legal basis under the UN Charter. The Security Council had not approved the use of force and the United States had no plausible claim of self-defense. In earlier humanitarian crises, the UN Security Council mandates served mainly as helpful facts to bolster claims of presidential authority. Without such a mandate in the Kosovo campaign, international law was all but invisible in the constitutional war-powers debate. Even congressional critics of Clinton’s unilateralism largely disregarded the international law questions.

A decade later, President Obama’s 2011 intervention in Libya would tie together many legal strands of these 1990s humanitarian missions: assertions of broad power to intervene, minimal role of UN mandates in constitutional arguments, and watering down the War Powers Resolution. When the UN Security Council authorized military action to protect civilians from slaughter by Libyan government forces, the United States joined an international coalition in carrying out that mandate. The Justice Department drew directly on its Haiti opinion from two decades earlier in concluding that U.S. operations – mostly airstrikes, intelligence gathering, and logistics for coalition partners – did not rise, constitutionally speaking, to the level of “war” requiring congressional approval.⁶³ The UN imprimatur barely factored in the analysis at all, save for boosting the point that the President was defending American interests. When operations extended beyond sixty days, the Obama Administration echoed Reagan-era arguments as to why the War Powers Resolution’s time limits did not apply – most notably, that the intensity of U.S. combat was mild. In making that case to Congress, the State Department Legal Advisor mentioned UN backing only in passing, to illustrate the limited scope of the mission, and therefore the limited scope of asserted presidential power.⁶⁴

Conclusion

In the last decades of the twentieth century, the United States went from waging superpower Cold War to putting out regional fires. A bipolar world order gave way to a briefly unchallenged U.S.-led system of collective security, one that by the late 1990s was already showing signs of strain. Consistently across all of these changes, American presidents cast the United States as the indispensable world leader – first as an anti-Communist defender of the free world, then as a global police force. Congress, meanwhile, was split over how far to stretch American military commitments.

During the Cold War, many political leaders had viewed each regional crisis as part of a much grander struggle, leading presidents to claim grand war powers to match. Even if the post–Cold War strategic context was new, the major war-powers issues during this period mostly repeated earlier debates: Could the President use force – and if so, how much or what type of force – without congressional approval? Could Congress require that the President cease military operations, and by what means? The answers had some new twists. For example, in the first half of this period, the Executive Branch advanced theories of very broad presidential power to use force. But in the latter half – when it faced no serious, foreseeable threat from a peer rival – it stressed limits that would apply to that power beyond a blurry threshold of “war.” In decades to come, executive branch claims about the President’s power to use force would continue to vacillate between asserting vastness and acknowledging possible limits.

For a moment in the early 1990s, it seemed that the UN Security Council was beginning to function as its original champions had hoped. One might have expected the organ’s post–Cold War revival to render older constitutional formulas obsolete, on the theory that UN approval could stand as a full substitute for any required congressional authorization. But while the UN’s approval offered international legitimacy, it scarcely touched constitutional logic. The scope of presidential powers to use force has always been contested. But with one possible exception – very brief and unrealized enthusiasm in 1945 for putting some U.S. forces in the UN Security Council’s hands – American political leaders have denied that international-law arrangements have altered constitutional ones. Historically, partisans on both sides of presidential war-powers debates have tried to interpret treaties and defense pacts within existing constitutional frameworks, not as substitutes for them.

In one respect, however, the period from 1980 to 2000 differed from earlier eras: The major war-powers controversies were almost entirely external. Under Reagan, George H. W. Bush, and Clinton, military planning and conflicts demanded no draft, no mass mobilization, and no major sacrifice at home – indeed, Americans even enjoyed a peace dividend. Constitutional debates thus looked outward, centering on how unilateral presidential force shaped events abroad. In 2001, war would come home, forcing those questions inward.