Bellum Romanum and Bellum Civile and the double standards towards civilian protection

A key feature of American warfare until the end of the twentieth century was the existence of a double standard regarding the levels of restraint towards enemy civilians. Originating in ancient Greece, drastically different levels of respect for civilian protection had profound effects on European and – by extension – American warfare. This double standard was finally eradicated in the late 1980s and 1990s, resulting in a significant strengthening of the principle of non-combatant immunity.Footnote ²

To investigate this current humanising trend, the article examines the different forms civilian protection has taken throughout the history of US warfare. First, however, it traces the conceptual origins of the double standards in ancient Greece before examining how they came to shape the American use of force. This short detour is important, for US warfare was modelled on key aspects of ancient Greek (and Roman) warfare, including the conceptual double standards which informed how force was employed by the ancient Greeks against those who were conceived as humans and sub-humans. Systematised by Roman law, these conceptual double standards were subsequently inherited by the Renaissance and the Enlightenment – and thereby became the legal foundation of Europe and, by extension, the US. In this process, the conceptual differentiation between Bellum Romanum and Bellum Civile that had originated in ancient Greece and Rome and that had characterised European warfare, came to persist in US warfare.Footnote ³ The article employs the concepts of Bellum Romanum and Bellum Civile as a means to conceptually reconstruct the different normative and legal restraints with which military force was employed.

In the context of ancient Greece, when Greek warriors fought other Greek warriors, they generally observed the unwritten conventions of city-state warfare. The so-called ‘Common customs of the Hellenes’ ensured that a highly ritualised and restraining code was honoured in intra-Greek warfare.Footnote ⁴ The restraint enshrined in these Hellenic customs, however, was only shown in intra-Greek wars; they did not exist in wars between Greeks and non-Hellenes. In conflicts against the latter, as during the Persian Wars (490–478 BC), Greek warriors waged unrestricted warfare.Footnote ⁵ The difference between these drastically different types of war was based on the concepts of Bellum Civile and Bellum Romanum.Footnote ⁶ The former codified the normative restraints on the use of force in order to maintain a high level of discrimination in war. In contrast, Bellum Romanum was a type of:

This type of warfare was inherently indiscriminate.

In applying only to certain peoples and not to others, these early conventions in war were particularistic in nature as the protection afforded by them only applied to Greeks. Towards non-Hellenes, a Greek warrior could and did behave without restraint. In other words, a double standard existed with respect to the normative restraints on the use of force.Footnote ⁸

The reason why Bellum Romanum rather than Bellum Civile was practised against non-Hellenes was located in a limited notion of humanity. Those living inside the respective historical conception of humanity were regarded as human beings and therefore subjected to the principles of Bellum Civile. Those living outside the conception of humanity were seen as sub-humans and were consequently subjected to the principle of Bellum Romanum. The limits and boundaries of humanity, or, in other words, the moral restraint on the use of force, were the fault lines between Bellum Civile and Bellum Romanum.

Bellum Romanum and Bellum Civile in seventeenth – nineteenth century US warfare

This normative double standard of restrained and unrestricted warfare was adopted throughout most of the European and – by extension – American history of warfare.Footnote ⁹ Humanity in the American context was defined as Christian, white, and civilised. All those outside these categories were dehumanised by labelling them infidels and savages. This distinction between intra – and extra-American standards of humanity inherited from the ancient Greeks, chivalric knights, and early European colonial powers resulted in the continued application of the double standard of morality in the use of force.Footnote ¹⁰ Within the American conception of humanity, normative restraints were increasingly complemented by legal restraints trying to salvage the decencies of chivalric warfare in the industrial age.Footnote ¹¹ Yet, these decencies were neither morally respected nor legally binding in wars waged against those considered to be ‘savages’ and ‘barbarians’.Footnote ¹²

The limited conception of humanity was sufficient justification for the conduct of a type of war against those outside humanity that – had it been practised in this form between Americans and Europeans – would have been considered as inhumane and unacceptable. And precisely because the dehumanisation of these outsiders had become the norm, Bellum Romanum was the standard military practice by Americans during their imperial expansion.

Underpinning America's continental expansion were the religious 1630 vision of America being ‘a city upon a hill’ and the political rationale of ‘Manifest Destiny’. A deeply religious nation, Americans perceived themselves as a Chosen People, forging a special covenant with God. Bestowed to them by Him, their destiny was to carve a New Jerusalem out of the wilderness.Footnote ¹³ ‘Manifest Destiny’ was an early nineteenth century vision proclaiming that the American people must redeem the land to the west, and to extend their sovereignty to its natural frontiers.Footnote ¹⁴ Coined by John L O'Sullivan, ‘Manifest Destiny’ thus referred to the conviction that superior institutions and culture gave Americans the God-given right, even an obligation, to spread their civilisation across the entire continent.Footnote ¹⁵ In their quest to dominate the continent from ocean to ocean, Americans regarded the indigenous Indian population that they encountered as sub-human obstacles to their push westwards.Footnote ¹⁶ Early colonialists and settlers defined the Indian tribes of New England as savages, subjecting them to unrestricted warfare. For example, George Washington, the first US President, described Indians as ‘beasts of prey, similar to the wolf, though they differ in shape.’Footnote ¹⁷ Lieutenant General William T Sherman, the commanding general in the wars against several Indian tribes, argued that:

During its westward expansion, the US government either dealt with Indian tribes by forcing their resettlement or by waging wars of total extermination against them.

The 1832 ‘Grand American Desert’ Plan and the 1834 ‘Indian Intercourse Act’ signed by President Andrew Jackson compelled the indigenous population to move from their natural habitat to allocated territories (so-called ‘permanent Indian country’).Footnote ¹⁹ Whenever these measures of forced resettlement met with resistance by tribes like the Cherokees or the Seminoles in Florida (1836–1842), American forces by default waged unrestricted warfare against them.Footnote ²⁰

Following the 1843 Oregon Settlement and the Mexican-American War (1846–1848), the strategy of permanent resettlement became obsolete. With Indian country no longer marking the official boundary of the US and unable to remove the indigenous population further West, the American government forced the remaining Indian tribes into reservations. Those tribes that were not in their allocated reservations by 31 January 1876 were assumed to be at war with the US. US military reaction against the latter turned into a long range strategy of annihilation.Footnote ²¹

In the Zeitgeist of the colonial age there was – at least from the perspective of the coloniser – nothing wrong with launching indiscriminate warfare against ‘savages’. Bellum Romanum could be practised against ‘uncivilised’ tribes as they were placed outside the conception of humanity. Theodore Roosevelt, who later became the twenty-sixth President of the US, publicly supported the virtual extermination of the American Indians on the grounds that they were an uncivilised race:

In the Red River War (1874–1875) and in the wars against the tribes of the northern plains the economic base of Indian communities (the buffalo herds) was destroyed and tens of thousands of Indians massacred. The result of waging Bellum Romanum was not only the annihilation of the military power of the Indian nations, but also the extinction of their independent way of life and culture.

At the same time, however, when American forces fought European powers as during the French and Indian War 1755–1763, the war of 1812, or the 1898 Spanish-American War, the unmitigated cruelty visited on the Indian nations by default gave way to a restricted way of fighting. White Europeans were generally regarded as living inside the conception of humanity and therefore had to be subjected to the principles of Bellum Civile.Footnote ²³ The moral conventions as well as early rules of international law, designed to ensure a high level of humanity in wars between ‘civilized’ nations, explicitly excluded colonial subjects from its provisions. International law only protected those deemed to be civilised, whereas ‘barbarians’ and ‘savages’ at best possessed rights to guardianship and punishment.Footnote ²⁴

American imperial expansion beyond the continent reproduced the same double standards. The US had always thought of itself as different from European colonial powers. At least in its own mind, it saw imperialism as an accidental by-product of the victory over Spain in 1898. Yet, finding itself in the possession of Puerto Rico and the Philippines after the 1898 War with Spain, America was prepared to pick up what the poet Rudyard Kipling termed ‘the White Man's Burden’.Footnote ²⁵ This famous poem enshrined in the US perception an image of the Filipinos as ‘fluttered folk and wild […] sullen peoples, half devil and half child.’Footnote ²⁶ For Americans, there was a clear link between fighting Indians on the Western frontier and Filipinos in Asia. During the Philippine War (1898–1902), US forces under Major General Arthur MacArthur, a former Indian fighter on the Western plains, burned entire towns, tortured civilians, and slaughtered the local population.Footnote ²⁷ His ‘General Order 100’ eliminated the neutrality of the civilian population and orders were given to kill everyone above the age of ten, slaughtering as many as 200,000 civilians in the process.Footnote ²⁸

The moral issues raised by this practice of unrestricted violence and – in the case of the Indian nations – genocidal warfare were insufficient to either rattle the confidence of the American people in their assumed right to extend the frontiers against the wishes of indigenous inhabitants or to penetrate their self-understanding of the modern world as progressive and peaceful.Footnote ²⁹ The reason for this was that those on the receiving end of colonial violence were non-Whites, non-Christians, and sub-humans who at best had to be treated as infants that needed to be educated and punished. As the Zeitgeist of modern societies aimed at the re-making of mankind, the social engineering of humans and the annihilation of entire ‘hordes of barbarians’ were part of the progression of the modern human project. As a result, ethnic cleansing and genocide became constitutive of progress.Footnote ³⁰ The perceived limits of humanity remained the fault lines between Bellum Romanum and Bellum Civile.

The blurring of Bellum Romanum and Bellum Civile in the age of modern industrial warfare

Compared to the age of empire, the boundaries of humanity changed significantly in the age of modern industrial warfare, thereby shifting the fault lines between Bellum Civile and Bellum Romanum. The principal effect of Modernity was to further constrict this already limited definition of humanity. By further reducing the definition of humanity to exclusive groups such as the race, the ethnic group, the class, and the nation, the group of those living outside humanity was effectively enlarged and included whites and non-whites, Americans as well as non-Americans. The boundaries of inside/outside therefore shifted with the result that the fault lines between Bellum Romanum and Bellum Civile went straight through the American and European continents. In other words, more human beings were excluded from the notion of humanity compared to the imperial age. Accordingly, Bellum Romanum, previously only practised by whites against non-whites, slowly started seeping into the wars fought among Americans and Europeans.

Why did this happen? Modernity brought a displacement of metaphysics from God onto History as the grand narrative.Footnote ³¹ It replaced a religious division of humanity with a secular one. History was no longer pre-ordained or subject to divine intervention, but subject to mankind. In the modern age, women and men were no longer objects but subjects of History.Footnote ³² During the course of the Enlightenment, a dialectical struggle over different concepts of Historical progress emerged in which Liberalism and Rationalism gave rise to the powerful intellectual and political currents of the counter-enlightenment that were outspokenly anti-liberal and anti-positivist, such as Romanticism, Socialism, and Fascism.Footnote ³³ As a consequence, the modern age turned into a struggle for History between those who saw themselves as agents pushing History into the future by forging new world orders.Footnote ³⁴ The race, the nation, the ethnic group, and the class served as secular religions by offering an entire worldview that justified sacrifice.Footnote ³⁵

In this dialectical struggle between different concepts of History, war was more than a mere instrument of policy. War was a medium for progress, social engineering, and political change because it was through the means of war that the modern individual became an agent of History.Footnote ³⁶ According to Mark Mazower, the three major concepts of History inherently shared the will to forge a New World Order:

In their quest to make History, no compromise was permitted. All three ideologies believed in the final showdown where the forces of the future would prevail over the forces of the past. All three saw themselves destined to remake society and to remake the world in a New World Order for mankind.

The total and uncompromising nature of modern ideologies allowed for the dehumanisation of others outside their nationalistic, racial, and/or ideological boundaries. They divided the universe into forces of light and forces of darkness, thereby labelling outsiders as sub-humans, beasts, or barbarians.Footnote ³⁸ The concepts of History laid the legitimate grounds upon which unrestricted warfare and unprecedented cruelty against entire societies could be waged in the course of the twentieth century.Footnote ³⁹ Once other nations had been dehumanised, the lawlessness with which war was practised outside the US and Europe could no longer be kept from seeping into wars between them. As a result, the distinction between Bellum Romanum and Bellum Civile started breaking down.

Once the technology and scientific innovations of industrialisation could give full reign to killing, modern wars became total – encompassing every aspect of private and public life.Footnote ⁴⁰ This rising curve of barbarism became most obvious in relation to civilians who became proper; in some cases even the main target of the modern war machine.

Yet, it was the American Civil War (1861–1865) which provided the first modern glimpse of total war.Footnote ⁴¹ The Civil War witnessed the departure from customary practices that had previously prevailed in wars between ‘civilized’ armed forces. Confronted with unrestricted warfare, first attempts were made to salvage the decencies of Bellum Civile by codifying standards of civilised behaviour in legal terms. The ‘Instructions for the Government of Armies of the US in the Field’ (which came to be known as the Lieber Code) were issued to the Union Army on 24 April 1863 and not only prepared the way for the calling of the 1874 Brussels Conference but also had profound effects on the shaping of the overall evolution of IHL as codified by the Hague and Geneva Conventions.Footnote ⁴² But even though the Lieber Code aimed at reigning in the worst annihilationist tendencies of the Civil War, it failed to prevent the degeneration of the conflict.Footnote ⁴³

This degeneration was slow but gradual, evolving from the early restraint in Unionist and Confederate practices to increasingly directing military force at the enemy's economic resources and civilian population. The strategy of annihilation of General Ulysses S Grant emerged out of the realisation that wars of attrition made the attainment of decisive victory in battle more difficult, and that conciliatory politics had failed to bring the Secessionists back into the Union.Footnote ⁴⁴ Although the Civil War was still far off the later contests of rival productive capacities like those during the Second World War, the logistical requirements of both mass armies had already become big enough to make war against the enemy's resources and support base begin to appear a tempting prospect.Footnote ⁴⁵

The resulting Unionist strategy, executed by Unionist Generals Grant, Sherman, and John Pope, was not only designed against the enemy industry and land, but also developed into a deliberate strategy of terror directed at the civilian population. As Sherman argued, ‘we are not only fighting hostile armies, but a hostile people and must make old and young, rich and poor, feel the hard hand of war.’Footnote ⁴⁶ This understanding of modern war as a conflict between peoples beyond the contest of armed forces led to campaigns, most famously Sherman's march to the sea as well as the forced evacuation and the burning of Atlanta, which aimed at carrying the destruction of war straight to the enemy people.Footnote ⁴⁷ By arguing that ‘War is Hell’, Sherman saw himself entitled to do whatever he considered militarily necessary to defeat the Confederate Army.Footnote ⁴⁸ The Union's objective became the complete destruction and total submission of the South, causing the practice of Bellum Romanum to seep into conflicts between white Americans.

The US and – shortly thereafter – modern Europe experienced a type of war that aimed ‘not just [at] the overthrow of the enemy's political power but [at] the physical destruction of his entire society.’Footnote ⁴⁹ In World War Two, political and military decision makers on the sides of the Axis and Allies alike regularly used arguments of military necessity to override concerns for civilian protection, as during the strategic bombing campaigns and the dropping of the atomic bombs.Footnote ⁵⁰ As modern war was waged as a struggle for the survival of the state and the political community, the ideological threats posed by those outside humanity were regarded as so horrific and imminent as to make concern for civilian protection redundant.

But even within total warfare, important differences existed in the level of respect for civilians shown by the participating armed forces. For example, Hitler's Blitzkrieg campaigns in Western Europe and Africa remained relatively restrained compared with the ideologically driven ‘Vernichtungskrieg’ in the East that aimed at the total annihilation of the ‘Jewish-Bolshevik Revolution’.Footnote ⁵¹

In the American case, a similar difference existed between the levels of restraint shown by US soldiers in the European and Pacific theatres of the war. Although America waged total war on both societies, several studies show how racial and ideological factors help to explain why US behaviour against imperial Japan was considerably more unrestricted and barbaric than against Nazi Germany.Footnote ⁵² Despite Hitler's orgy of violence on the Eastern Front and the execution of the Holocaust, it was the Japanese rather than the Germans who were dehumanised as vermin, ‘beastly little monkeys’ or ‘apes in khakis’.Footnote ⁵³ Analysing the role race played in shaping American attitudes during the Pacific War, Theo Farrell argues that:

No Japanese equivalent to the ‘Good German’ existed in the American consciousness; instead, they were seen as a race or even a species apart.Footnote ⁵⁵ The Japanese were saddled with racial stereotypes that Americans had applied to non-whites for centuries during their conquest of the New World, the slave trade, the Indian wars, and the US conquest of the Philippines.Footnote ⁵⁶ Such dehumanisation not only made possible the decision to make the Japanese population the direct target of US conventional and nuclear attacks, but also explained why the American war in Asia was more unrestricted and merciless than in the European theatre.Footnote ⁵⁷

To give an example: Under the Executive Order 9066, signed by President Roosevelt on 19 February 1942, the US government incarcerated 110,000 Japanese-Americans en masse but failed to take any comparable action against residents of German or Italian origin. In Europe, but not in the Pacific, one distinct feature was the lack of racial hatred for the enemy; the average American GI was found to hate Germans less than ‘Japs’.Footnote ⁵⁸ These racist undertones were also reflected in American bombing policies as well as the treatment of (and refusal to take) Japanese Prisoners of War (POW).Footnote ⁵⁹ Moreover, the US Air Force (USAF) held to comparatively restricted bombing practices over Germany (such as flying daytime raids in order to ensure higher levels of precision and using lower numbers of incendiary or napalm bombs).Footnote ⁶⁰ No such considerations of restraint existed in the American campaigns over Japan.Footnote ⁶¹ Even within total war, therefore, important differences existed in the levels of respect the US showed to civilian populations.

The modern age reduced the boundaries of those considered to be humans and thereby enlarged the group of those who were considered to be outside humanity. The fault line of those outside humanity now included whites and non-whites (anyone belonging to a different race or following a different ideological Weltanschauung). The process of the decline of moderation in wars between Western industrialised powers marked the breakdown of the distinction between Bellum Romanum and Bellum Civile for it steadily regressed modern societies into an age of barbarism. Comparing America's modern industrial wars with its earlier colonial wars reveals a clear dehumanising trend.

The humanising trend

This dehumanising trend in modern US warfare was reversed in the post-1945 world. The resulting humanising process, however, was slow to evolve and only grew gradually. The first indications of this long process towards the strengthening of the principle of non-combatant immunity came through the Geneva Conventions of 1949 and could be witnessed on the Korean Peninsula and in Indochina. It was during the Korean and (crucially) Vietnam Wars that the racial undertones and ideological absolutes that had previously been employed to justify the American practice of Bellum Romanum started ringing hollow.

For a considerable period of time, however, racial hatred still coloured American views of both conflicts in ways that often found expression in language, imagery, and practices not dissimilar from the racism of the Philippine and Pacific Wars.Footnote ⁶² Moreover, it was in abstract ideational terms that Americans saw both conflicts as a test of their nation's will and readiness to confront and ultimately contain Communism. Based on the ‘domino theory’, Korea and Vietnam were conceived as part of the Cold War Manichean struggle between the forces of good and evil in which the US had to prevail in order to save humanity from Communism.Footnote ⁶³

On this ideological level, Korea and (in its early phase) Vietnam deeply appealed to America's sense of historical mission and duty to test its character and destiny against an enemy that was the antithesis of everything it stood for – Communism.Footnote ⁶⁴ Americans were prepared to support the ‘Long Twilight Struggle’ which required sacrifice and justified unrestricted warfare against the indigenous population of both countries.Footnote ⁶⁵

Despite the invocation of racial and ideological absolutes analogous to the ones that had justified the dehumanisation of US adversaries in earlier conflicts, a new American sensitivity towards civilian casualties could nevertheless be detected in the Korean War. In his study of the ‘bombing norm’, Ward Thomas shows that:

The sources of this emerging international sensibility in part came from the horrors and devastating suffering caused by World War II. In particular the Nazi atrocities, the indiscriminate nature of Allied strategic bombing as well as the dropping of the atomic bombs on Japan had started to render such military practices unjustifiable in the eyes of the international community.Footnote ⁶⁷ Both the proclamation of the Universal Declaration of Human Rights of 1948 and the Geneva Conventions of 1949 were designed to recognise the equality of all human beings and to endow civilians with legal protection from wanton violence. The four Geneva Conventions in particular, building upon and expanding the rules of modern war as set out in the Lieber Code and the Hague Conventions of 1899 and 1907, codified the norms prohibiting the targeting of civilians in wars.Footnote ⁶⁸ The codification of these humanitarian norms, Farrell argues:

This is not to deny that the American military subjected Korean cities to strategic bombing and incendiary raids that aimed at civilian morale and resulted in hundreds of thousands of deaths. In fact, Thomas acknowledges that the emerging norm of civilian protection was not only far from being internalised by the US military but also not powerful enough to prevent the use of strategic bombing despite growing international criticism. Post-WWII, in other words, a new norm was emerging which was bumping up against the old norm of Bellum Romanum. At the same time, however, the new norm

This newly emerging norm could also be witnessed in the nuclear taboo that came to shape US policy following the bombing of Hiroshima and Nagasaki. As Farrell shows in his study on the origins and institutionalisation of the nuclear taboo, American policymakers recognised a normative prohibition on the use of nuclear weapons (except as a last resort in retaliation for a nuclear attack) soon after the Second World War. US Presidents from Harry S Truman to George H W Bush conceived the use of atomic weapons against non-nuclear powers either as morally wrong per se or as unacceptable by (world) public opinion.Footnote ⁷¹ In relation to strategic bombing and the use of nuclear weapons, the era of the Korean War therefore saw the beginning of a change in American attitudes towards the safeguarding of enemy non-combatants.

Concerns for civilian protection became even more evident in the Vietnam War. Far more than in Japan or Korea, the growing sensitivity about civilian casualties served as an important constraining factor on America's bombing strategies.Footnote ⁷² In Vietnam, the same fear of a potential Soviet or Chinese Communist intervention that had already influenced US decision makers during the Korean War placed significant limitations on US bombing practices in North Vietnam.Footnote ⁷³ The US only started to escalate its military operations in Vietnam (such as the mining of Haiphong Harbour and the Christmas Bombing) after the opening to China and détente with the Soviet Union was already underway by 1972. This demonstrates the constraining effects that the fear of escalation with Moscow or Beijing had on US war making. In contrast to the Korean War, however, the targeting of densely populated areas such as Hanoi and Haiphong or the country's dam and dike systems was generally avoided throughout the war, indicating a far greater emphasis on the avoidance of civilian casualties than in Korea.Footnote ⁷⁴ By imposing significant restrictions on target selection, the civilian authorities in the White House and Pentagon not only tended to overrule the US military, but also rejected the requests by the Joint Chiefs of Staff (JCS) and General William Westmoreland, Commander of American Forces in Vietnam (1964–1968), for further escalation and, as in 1967, for an all-out war.Footnote ⁷⁵ Both President Johnson and his successor Richard M Nixon were acutely aware of the political costs that resulted from collateral damage and accordingly placed considerable emphasis on avoiding civilian casualties. As a result, many targets that could have been lawfully struck were placed off-limits such as the ‘restricted’ and ‘prohibited areas’ around Hanoi and Haiphong.Footnote ⁷⁶

The evidence of the bombing practice in Vietnam suggests that the sensitivity about civilian casualties had grown since World War II and the Korean War. The relative constraint in the use of air power against Vietnam indicated the beginning of a shifting of boundaries between those inside and outside the American definition of humanity. The norm of non-combatant immunity began to impose restraints on the killing of enemy civilians who had previously been located outside humanity. Subjecting the Vietnamese people to the unrestricted warfare of Bellum Romanum in the form of strategic bombing could no longer be legitimated.

In contrast to this change in bombing practices, the overall American conduct of the ground war in Vietnam remained indiscriminate and inhumane. Relying heavily on artillery and airpower to dislodge the enemy, the US waged a furious war against Vietcong and North Vietnamese base areas. In the course of the Indochina War, the US dropped seven million tons of bombs, more than twice the total bomb load dropped by all the nations in WWII combined.Footnote ⁷⁷ In addition, American counter-insurgency campaigns saw the establishment of free-fire zones in South Vietnam (in which all persons who remained within them were targeted without restraint). Villages suspected of harbouring Vietcong were subjected to ‘search and destroy’ operations or forced to resettle in the strategic hamlet relocation project.Footnote ⁷⁸ Combat pressure for a high body count, the belief by many US soldiers in the ‘mere-gook-rule’ (that is, that Vietnamese life was expendable and not protected by IHL), and the semi-official rule that ‘as long as it's dead and Vietnamese, it's Vietcong’, resulted in an inhumane and indiscriminate ground campaign.Footnote ⁷⁹ The symbolic failure of the ground campaign came on 16 March 1968 at My Lai, when 571 unarmed Vietnamese civilians were massacred by a platoon of US soldiers.

The Vietnam War therefore did not clearly fit into the category of either Bellum Romanum or Bellum Civile. The relative restraint practised during the US bombing in Vietnam in comparison to previous practices in World War II and Korea indicated a level of humanity that went beyond the practice of Bellum Romanum. However, the relatively unrestricted conduct by US forces on the ground fell well short of the practice of Bellum Civile. Thus, the Vietnamese people were subjected to a US strategy that fell somewhat uneasily between Bellum Romanum and Bellum Civile. However, this nevertheless indicated – in comparison to earlier US wars – a shift in the location of the fault lines between those previously considered inside and outside of humanity.

Despite these significant changes, the public outcry at the cruelty American soldiers visited upon the Vietnamese people also demonstrated the extent to which the conduct of the war was out of line with the public's moral expectations at the time. According to Michael Walzer, the feelings expressed by most of the war's opponents ‘had to do with the systematic exposure of Vietnamese civilians to the violence of American warmaking.’Footnote ⁸⁰ In other words, opponents of the conduct of the war argued that US military operations did not sufficiently protect Vietnamese civilians.

Such sentiments can be explained through the socio-political changes occurring in the US. Racial discrimination within American society only started to come to an end in the mid 1950s. On 17 May 1954, in the case of ‘Brown v. the Board of Education’, the US Supreme Court ended federally sanctioned racial segregation in public schools by ruling unanimously that ‘separate educational facilities are inherently unequal.’Footnote ⁸¹ A groundbreaking case, the ruling overturned the decree of ‘Plessy v. Ferguson’ (1896), which had declared ‘separate but equal facilities’ constitutional and which had been used for generations to sanction rigid segregation.Footnote ⁸² However, the landmark ruling in 1954 merely referred to public education facilities, leaving other areas of public life unaffected. Furthermore, implementation of the Supreme Court decision was slow, especially in the South where resistance to desegregation was the strongest. The most visible confrontation erupted in Little Rock, Arkansas in 1957, when President Dwight D Eisenhower had to send the National Guard to protect the newly gained rights of African Americans.Footnote ⁸³ Over the course of the next two decades, however, the National Association for the Advancement of Coloured People (NAACP) used the precedent of ‘Brown v the Board of Education’ to challenge segregation in other areas of American society. It thereby gradually expanded black civil rights and provided the legal foundations of the grass-roots Civil Rights Movement that started taking shape in the mid-1950s and 1960s.Footnote ⁸⁴ Thus, by the time of the Vietnam War, the Civil Rights Movement had made important strides and brought about significant change. The dehumanisation of African Americans had been declared unconstitutional at home, thereby undermining racial arguments that previously sanctioned indiscriminate force against indigenous people abroad and at home.

Against this wider context, and in addition, the ideological arguments which had justified the dehumanisation of others and the cruelty against them started disappearing. Americans' unfettered ideological belief in the containment of Communism, the domino theory, and the spreading of liberty, which had mobilised the nation in Korea and during the early years of Vietnam, started breaking down with the Tet Offensive of 1968. With the old racially and ideologically motivated arguments no longer ringing true, the ability of the American public to dehumanise others became significantly reduced.Footnote ⁸⁵

The Tet Offensive was the ‘military and political continental divide’ of the Vietnam War.Footnote ⁸⁶ It shattered US optimism and formed the turning point in the public and media support for the war, both of which turned from neutral and supportive to critical towards and fully against the continued involvement in Vietnam.Footnote ⁸⁷ In the eyes of the US public, the media, and the majority of the political class, Tet symbolised what Vietnam had become in spring 1968, a quagmire where military operations did not necessarily have anything to do with the perception of the value or course of the war.

The media coverage re-enforced this transformation of the American conscience for it implicated the American people in the conduct of the war for the first time.Footnote ⁸⁸ Throughout the conflict, camera teams and war photographers captured the cruelty visited upon the Vietnamese people in the name of containment. This footage severely disenchanted the American people for it created a dissonance between their image of themselves as noble, innocent liberators and the savage reality generated by their soldiers on the ground.Footnote ⁸⁹ The war in Indochina was not only delegitimised because of the mounting numbers of US body bags, but also because it was fought inhumanely.

What had changed in the late 1960s in US society was that the enemy was increasingly recognised as a fellow human being rather than being dehumanised on the grounds of political affiliation, race, religion, or colour. This development slowly started to alter the conscience of the American people regarding the cruelty directed against the Vietnamese. The changes in racial and ideological understanding slowly caused Americans to re-evaluate their relationship with the Vietnamese people. The latter became part of an expanding notion of humanity as Americans started gaining what Richard Rorty calls the imaginative ability ‘to see strange people as fellow sufferers.’Footnote ⁹⁰ This process of ‘self-reflexivity’ lies at the heart of the refusal to recognise humanity as the incarnation of something larger than the individual such as God, religion, race, or ideology. In other words, the old ideational absolutes have been eroded as a justification for the legitimacy of Bellum Romanum.Footnote ⁹¹ Instead, Christopher Coker argues,

This is important for it removes any philosophical or moral defence of cruelty.

Yet the war in Vietnam created a dissonance precisely because the conduct of the war – as seen on television every day – was out of line with the public feeling that the limits imposed on the use of force were morally insufficient.Footnote ⁹³ This gap between military practice and public moral expectations was particularly interesting because US military practice in Vietnam was comparably more discriminate than during the wars against Japan and Korea. This means that despite the early indications of a historical trend towards higher levels of respect for the principle of non-combatant immunity, US warfare in Vietnam was not discriminate enough to be legitimate in the eyes of the American people. Thus, US warfare was forced to close the gap between its own practice and public expectations in order to become legitimate again. Whatever the moral argument, there was now a strategic reason for the US military to fight justly if it wanted to maintain public support at home.Footnote ⁹⁴ The direct result of the political fallout from Vietnam was the beginning of the systematic internalisation of the principle of non-combatant immunity into US military doctrine, training, and even the development and procurement of weapons systems.Footnote ⁹⁵

This humanising trend in US warfare continued to gather strength after the end of the Cold War. During the 1991 Persian Gulf War a historically unprecedented emphasis was placed on minimising direct casualties to civilians.Footnote ⁹⁶ Limiting the risks to enemy civilians was a major objective shared among American military and political leaders. By carefully differentiating between the Iraqi regime and the Iraqi people, the rhetoric of key decision makers displayed a principal understanding that the war was to be conducted between armed forces and that civilians should be shielded from the violence.Footnote ⁹⁷ The President and his generals believed that the American people would not tolerate the slaughter of civilians. For Walzer, the readiness of the American leadership to employ moral arguments and rationalisations that:

As Walzer goes on to show, President Bush and Generals Norman Schwarzkopf and Colin Powell incorporated a way of rationalising and justifying their way of making war that had remained external to American decision makers during Vietnam.Footnote ⁹⁹

The difference of the situation in the early 1990s from that of the Vietnam era was not merely rhetoric but was also reflected in the way in which US strategy was designed to minimise collateral damage. The American air campaign for instance excluded numerous potential targets because they were considered culturally or religiously sensitive. Furthermore, all other targets underwent extensive legal review for their proximity to civilians, school, hospitals, or mosques.Footnote ¹⁰⁰

Overall, these concerns for civilian protection translated into a highly restrained and precise targeting strategy which produced around 3,000 civilian casualties – a low figure compared to both the number of civilian casualties in previous American wars and the amount of ordnance dropped.Footnote ¹⁰¹ It is for that reason that Operation Desert Storm has been interpreted as one of the most intense and simultaneously most discriminate air campaigns in history.Footnote ¹⁰²

The 1991 Persian Gulf War showed the extent to which the dehumanising trend in American warfare had been reversed in the course of five decades. The changes in US targeting practices indicate a clear progression of the importance of civilian protection since WWII.Footnote ¹⁰³ This humanising trend was slow to evolve and only accelerated after the Vietnam War. Yet, by the end of the Cold War, American warfare progressed substantially towards closing the gap that opened in Vietnam between indiscriminate military practices and the public's expectations of how war should be conducted. In other words, US warfare transcended the racism as well as the ideological Weltanschauung that had previously dehumanised others and had justified the fundamentally indiscriminate practice of Bellum Romanum. This tectonic shift – in combination with improvements in weapons technology – has elevated the avoidance of collateral damage to one of the central features of contemporary American warfare.Footnote ¹⁰⁴ The ‘happy marriage’, as Farrell termed it, of Western-derived norms of international law with American precision military technology, has permitted the US to limit civilian deaths during contemporary conflicts for it possesses ‘unprecedented capability to create discriminate destruction.’Footnote ¹⁰⁵ Due to the acquisition of new military technology and the restructuring of its forces following the Vietnam War through the Revolution in Military Affairs (RMA) and net-centric warfare, the US military has been able to emphasise precision in the pursuit of minimal civilian casualties.Footnote ¹⁰⁶

Today, American firepower is concentrated on the enemy's military and efforts to minimise the level of harm to non-combatants in target states have informed US targeting policies.Footnote ¹⁰⁷ The increased involvement of military lawyers in the target and weapons selection process during and since the Gulf War has contributed significantly to US operations falling in line with IHL.Footnote ¹⁰⁸ This development is historically important for it has reversed the long twentieth century dehumanising trend in American campaigns.

Contemporary US warfare and the legal-moral nexus