The 2003–2011 American war and subsequent counterinsurgency and nation-building efforts in Iraq represent the most heavily polled foreign policy event in the history of modern public opinion research. As such, the Iraq conflict offers a unique opportunity to investigate the predictive efficacy of a whole host of theories concerning the causes and effects of public opinion on American foreign policy. Not surprisingly, numerous scholars have sought to take advantage of this opportunity. Into this fray has now stepped Ole Holsti, one of the most widely respected scholars of public opinion and American foreign policy.

In his new book American Public Opinion on the Iraq War, Holsti reviews a massive trove of public opinion data spanning nearly the full duration of the conflict (2003–10) in a three-pronged effort to 1) offer a definitive explication of public opinion on the Iraq War, 2) place public opinion on Iraq into thematic and historical context, and 3) shed new light onto a long-running debate among public opinion scholars concerning the fundamental nature of American public opinion.

To address the third goal, Holsti employs data from the Iraq conflict to informally test competing views of American public opinion on foreign policy either as ill-informed and volatile—which Holsti elsewhere famously termed the “Almond-Lippmann Consensus” (“Public Opinion and Foreign Policy: Challenges to the Almond-Lippmann Consensus Mershon Series: Research Programs and Debates,” International Studies Quarterly 36 [December 1992]: 439–66)—or alternatively as essentially rational and sensibly responsive to events, at least on average. Holsti identifies the latter perspective as the “low information rationality” perspective (p. 30), associated with more contemporary scholars such as Sam Popkin, who coined the term in The Reasoning Voter (1994).

With respect to the first two goals, in addition to reviewing and analyzing a dizzying array of opinion data trends (Goal 1), Holsti places public opinion on Iraq into a broader perspective (Goal 2). He pursues the latter by reviewing the history of US (Chapter 1) and British (touched upon in Chapter 2) interventions in Iraq over the past century; by placing Iraq into the broader context of public attitudes toward foreign policy over multiple decades and across a variety of topics, ranging from the Cold War to global terrorism (Chapter 4); and by considering some broader implications of Iraq for the scholarly understanding of public opinion and its role in American foreign policy (Chapter 6).

In Chapters 2, 3, and 5, Holsti devotes significant attention to a comparison of Iraq to prior American conflicts, particularly Vietnam and the 1991 Persian Gulf War. However, these chapters focus more directly than the others on public opinion regarding the Iraq War, including both its form—in the aggregate (Chapter 2) and broken out by party (Chapter 3)—and its influence (or lack thereof) on the Bush administration's policy decision making (Chapter 5).

Although others, including Holsti himself in prior work, have described much of the historical material included herein, he ties these many strands together into a single, coherent narrative. He does so with the fluidity and authority of one who has spent many decades studying the topic. For instance, in his consideration of the partisan divide on Iraq, Holsti places in stark relief some of the most persuasive evidence I have seen of a fundamental change in American public opinion regarding foreign policy, which he attributes to the divisive effects of the Vietnam War. He shows that there really was a virtual bipartisan consensus on a variety of major foreign policy issues that lasted for nearly two decades following World War II (1946–63), during which the average partisan divide across 11 major foreign policy issues included in Gallup surveys (p. 80) was about 2.8 percentage points. This contrasts sharply with the post-Vietnam period, 1977–2000, during which the average partisan gap in support across 13 major foreign policy issues polled by Gallup (p. 85) was more than 20 percentage points. He goes on to present overwhelming evidence that the partisan gap on support for the Iraq War dramatically eclipsed all other events on record, typically exceeding 50 percentage points. Though various scholars have investigated this partisan gap, it is nonetheless instructive to see the Iraq data placed into a broader historical context.

Holsti argues that the aggregate-level opinion data mostly support the low-information rationality perspective. He bases this conclusion primarily on two trends. The first is the gradual, sustained movement of the public away from its initial broad support for the conflict as circumstances on the ground began deteriorating, beginning in the summer of 2003, and as the Bush Administration's claims with respect to Iraq (on weapons of mass destruction, Saddam Hussein's ties to Al Qaeda, welcoming of American troops as liberators, etc.) were increasingly revealed as at best exaggerations and at worse outright falsehoods. The second is the turnaround in public attitudes regarding the likelihood of success in the aftermath of substantial and sustained declines in casualties following the 2006–7 troop “surge,” juxtaposed against the seemingly reasonable relative absence of change on the question of whether or not the war was “worth the cost.”

As persuasive as these aggregate patterns may appear, the question arises as to how one can square them with the vast partisan divides described in Chapter 3. The picture that emerges in that chapter is of two extreme polar opposite sets of beliefs that are impressively resistant to alteration in response to information or changes in events inconsistent with those beliefs. For instance, according to Table 3.4, as late as October 2006—at the height of the insurgency—nearly 60% of Republicans continued to believe that the war was going well, while in September 2007, 40% of Republicans continued to believe that Saddam was personally involved in 9/11. Conversely, in War Stories (2010), Tim Groeling and I found in a national survey we conducted in December 2007—six months after US casualties began declining, and by which time they had fallen to their lowest level in nearly four years—that Democrats and Independents, but not Republicans, continued to believe that casualty rates had not changed since the start of the surge.

If one superimposes the aggregate pattern described in Chapter 2 onto the partisan trends from Chapter 3, the former appears almost akin to a mathematical mean. Hardly anyone, except perhaps for a relatively small number of Independents, actually occupies this “rational” space along the aggregate curves. Consequently, it is difficult to square the collective appearance of a rational public with the individual-level evidence of public opinion driven largely by partisan political attitudes, which, as Gary Jacobson (A Divider, Not a Uniter, 2006) has shown, closely track partisan approval of President George W. Bush.

If anything, the partisan opinion patterns appear to support Richard Brody's elite indexing hypothesis (Assessing the President, 1991), according to which partisans in the electorate mostly fall in line behind their fellow partisan elites, either supporting or opposing the president and his policies depending on the cues sent down from above. Ironically, this latter view corresponds with Popkin's conception of “low information rationality,” which presumes precisely this sort of cue taking. The effect in this instance is that once Democratic elites turned against the war, Democratic partisans fell in line. So long as Republican elites continued to support the administration, so too did Republican partisans. Only a fairly dramatic and sustained change in events, belatedly acknowledged by Democratic elites, prompted the partial reassessment of Iraq that Holsti identifies with respect to the aftermath of the 2007 surge.

When Holsti turns from the sources of opinion to its effects, he asserts that the public “had almost no impact because the administration would likely have invaded Iraq even in the absence of public support,” adding that the president saw the public as “an entity to be ‘educated’ rather than as a source of useful policy guidance or even as a significant political barrier” (p. 141). Counterfactual claims are difficult to prove. Holsti musters an impressive array of suggestive evidence that the administration was bound and determined to go to war in Iraq, regardless of whether others, domestic or international, supported them. Yet he also documents the administration's impressive effort to “educate” the public and gain the support of the United Nations.

We will never know whether the Bush administration would, in fact, have invaded Iraq in the face of overwhelming public opposition. Even if we stipulate that it would have done so, absent a relatively permissive public opinion environment, it is unclear for how long the administration could have sustained the effort. It is easy to forget that the surge was the administration's last-ditch attempt, following the Republicans' 2006 midterm loss of Congress, to stem a rapidly rising political tide against the war. Had it failed to deliver tangible results fairly quickly, political reality may well have forced the president's hand. That said, it is also unclear whether one should interpret a public constraint that only begins to kick in after nearly four years of war as evidence for or against public opinion “mattering.” Again, we will never know.

On balance, the book's impressive documentation of public opinion regarding Iraq, as well as its location of opinion trends on the conflict within broader thematic and historical contexts, represent valuable contributions. The author's level of success in evaluating theoretical propositions concerning the causes and consequences of public opinion on foreign policy is somewhat more ambiguous. That said, the latter is clearly a secondary goal of the book, and the former goals are of sufficient importance to make this an important contribution to the emerging scholarly understanding of public opinion regarding the Iraq conflict, both on its own terms and as a more general case study of American public opinion regarding foreign policy.