It might be argued that if Hussein committed mass atrocities in the past, his overthrow was justified as a way to prevent his resumption of such atrocities in the future. However, humanitarian intervention may be undertaken preventively only if slaughter is imminent. There must be evidence that large-scale slaughter is in preparation and about to begin unless militarily stopped. No one seriously claimed before the war that Hussein’s government was planning imminent mass killing, and no evidence has emerged that it was. There were claims that the government, with a history of gassing Iranian soldiers and Iraqi Kurds, was planning to deliver weapons of mass destruction to terrorist networks, but no supporting proof of these allegations has yet emerged. There were also fears that the government might respond to an invasion with the use of chemical or biological weapons, perhaps even against its own people, but no one seriously suggested such use as an imminent possibility in the absence of an invasion.

The Last Reasonable Option

The lack of ongoing or imminent mass slaughter in March 2003 was itself sufficient to disqualify the invasion of Iraq as a humanitarian intervention. Nonetheless, in light of Hussein’s ruthless past, it is useful to examine the other criteria for humanitarian intervention. For the most part, they too, were not met.

As noted, because of the substantial risks involved, an invasion qualifies as a humanitarian intervention only if it is the last reasonable option to stop mass killings. Since there were no ongoing mass killings in Iraq in early 2003, this issue technically did not arise. But it is useful to explore whether military intervention was the last reasonable option to stop what Iraqi abuses were ongoing.

It was not. At least one other option should have been tried long before resorting to the extreme step of military invasion—criminal prosecution. There is no guarantee that prosecution would have worked, and one might have justified skipping it had large-scale slaughter been underway. But in the face of the Iraqi government’s more routine abuses, this alternative to military action should have been tried.

To be sure, an indictment is not the same as arrest, trial, and punishment. A piece of paper will not stop mass slaughter. But as a long-term approach, an indictment held some promise. The experiences of former Yugoslav President Slobodan Milosevic and former Liberian President Charles Taylor suggests that an international indictment profoundly discredits even a ruthless, dictatorial leader. That enormous stigma tends to undermine support for the leader, both at home and abroad, often in unexpected ways. By allowing Hussein to rule without the stigma of an indictment for genocide and crimes against humanity, the international community never tried a step that might have contributed to his removal and a parallel reduction in government abuses.

Humanitarian Purpose

A humanitarian intervention should be conducted with the aim of maximizing humanitarian results, since an intervention motivated by purely humanitarian concerns probably cannot be found. Governments that intervene to stop mass slaughter inevitably act for other reasons as well, but a dominant humanitarian purpose is important because it affects numerous decisions that can determine the intervention’s success in saving people from violence.

Humanitarianism, even understood broadly as concern for the welfare of the Iraqi people, was at best a subsidiary motive for the invasion of Iraq. The principal justifications offered in the prelude to the invasion were the Iraqi government’s alleged possession of weapons of mass destruction, its alleged failure to account for them as prescribed by numerous UN Security Council resolutions, and its alleged connection with terrorist networks. US officials also spoke of a democratic Iraq transforming the Middle East. In this tangle of motives, Hussein’s cruelty toward his own people was mentioned, sometimes prominently, but, in the prewar period, it was never the dominant factor. This is not simply an academic point; it affected the way the US attacks were carried out, to the detriment of the Iraqi people.

Most significant, if invading forces had been directed to maximize the humanitarian impact of an intervention, they would have been better prepared to fill the security vacuum that predictably was created by the toppling of the Iraqi government. It was entirely foreseeable that Hussein’s downfall would lead to civil disorder. The 1991 uprisings in Iraq were marked by large-scale summary executions. The Iraqi government’s Arabization policy raised the prospect of clashes between displaced Kurds seeking to reclaim their old homes and Arabs who had moved into them. Other sudden changes of regime, such as the Bosnian Serb withdrawal from the Sarajevo suburbs in 1996, have been marked by widespread violence, looting, and arson.

In part to prevent violence, the US Army Chief of Staff before the war, General Eric K. Shinseki, predicted in 2003 that “several” hundred thousand troops would be required. But the civilian leaders of the US Pentagon dismissed this assessment and launched the war with considerably fewer combat troops—some 150,000. Coalition troops were quickly overwhelmed by the enormity of the task of maintaining public order in Iraq. Looting was pervasive. Arms caches were raided and emptied. Violence was rampant.

The problem of understaffing was only compounded by the failure to deploy an adequate number of troops trained in policing. Regular troops are trained to fight—to meet threats with lethal force. But that presumptive resort to lethal force is inappropriate and unlawful when it comes to policing an occupied nation. The consequence was a steady stream of civilians killed when coalition troops, on edge in the face of common but unpredictable attacks by resistance elements, mistakenly fired on civilians. That only increased resentment among Iraqis and fueled further attacks. Troops trained in policing—that is, trained to use lethal force as a last resort—would have been better suited to conduct occupation duties in a humane fashion. But the US Pentagon has not made a priority of developing policing skills among its troops, leaving relatively few to be deployed in Iraq.

Compliance with Humanitarian Law

Every effort should be made to ensure that a humanitarian intervention is carried out in strict compliance with international human rights and humanitarian law. Compliance is required in all conflicts—no less for an intervention that is justified on humanitarian grounds. The invasion of Iraq largely met this requirement, but not entirely. Coalition aircraft took extraordinary care to avoid harming civilians when attacking fixed, pre-selected targets. But the coalition's record in attacking targets that arose unexpectedly in the course of the war was mixed.