Recently, President Trump announced that he will pardon former Army First Lieutenant Michael Behenna, who was convicted of executing a naked, unarmed prisoner in Iraq in 2008. He has indicated that he might also pardon a Blackwater contractor, Nicholas A. Slatten who was convicted for his part in the killings of 17 Iraqis and the wounding of 20 others in Baghdad in 2007.

In addition, there is the possibility that President Trump may also pardon two others who have not been tried yet: Navy Special Operations Chief Edward Gallagher and Army Special Forces Major Mathew Goldsteyn, both charged with killing prisoners. As one who led a Marine infantry platoon in Vietnam, I am predisposed to giving the benefit of the doubt to soldiers responding to ambiguous situations in warfare. But it appears to me that these cases are not ambiguous. They constitute atrocities and the president is wrong to pardon those who committed these acts. 

First, let me note that our enemies in recent wars, as well as in Vietnam, committed atrocities as a matter of course. But that does not justify winking at war crimes by our own soldiers. First of all, if soldiering is not merely wanton killing, if a military unit is more than an armed mob, soldiers are obligated to adhere to standards of honorable behavior. Samuel Huntington described the expertise of the professional military officer as “the management of violence.” War requires violence, but violence that is limited by a number of factors.

The West has placed three constraints on the conduct of warfare (jus in bello): proportion, discrimination, and the positive law of war. Proportion means that particular actions must be proportionate to legitimate military necessity and not involve needless suffering or destruction. Discrimination means that direct, intentional attacks on noncombatants, non-military targets, and those who have surrendered are prohibited. These constitute the laws of armed conflict and positive law of war.

Both derive from conventions, customs, the general principles of law, decisions in international law, and the writings of authorities. Standards regulating the conduct of war have followed two general paths: “Geneva law,” protecting victims and innocents, and “Hague law,” regulating land combat.

The most important conventions underlying the positive law of war (and therefore provide guidelines for the conduct of war) include the Hague Convention IV of 1907, the Geneva Convention of 1949, the 1977 Protocols to those conventions, and the Nuremberg trials following World War II. Customs that constrain the conduct of war include military necessity, humanity, and chivalry. Interestingly, the origin of these conventions can be traced to General Orders 100, the so-called Lieber Code, issued to the Union Army in 1863.

The key to applying the law of war to particular situations is the principle of military necessity. This principle holds that, subject to the principles of humanity and chivalry, a belligerent is justified in applying the amount of force necessary to achieve the complete submission of the enemy as soon as possible, with the least expenditure of time, life, and resources. Military necessity recognizes that a commander’s overriding concern is the accomplishment of his mission and the safety of his troops. One would not attack a populated area, increasing the risks of civilian deaths, unless such an attack were essential to the campaign.

Humanity is the self-evident recognition of the fact that one’s enemy is also a human being. Prohibitions against killing or torturing prisoners, and the generally recognized obligation to provide medical treatment to wounded prisoners, flow from this principle.

Chivalry is the customary recognition of the idea that the strong protect the weak. Soldiers do not declare war on women or children because it is dishonorable to do so. If women or children engage in war, however, the principle of military necessity usually takes precedence over chivalry.

The dilemma, of course, is how to judge an action, given the likely clash among the main conditions. Do all conditions have to be met? Must all be met equally, or do some conditions take priority over others? The general conclusion is that all conditions must be met. But there is also the necessity of prudence in evaluating actions in war. Different times and circumstances may make one condition more important than another. Moreover, a reasonable judgment that a condition was met in a particular situation can be changed as a result of additional experience, information, or insight.

Clearly, a soldier who executes a prisoner, either on his own or under orders, has acted in cold blood and consequently has committed a war crime. Proportionality, humanity, and chivalry guide this judgment.

Contrast the four cases above with a situation from the Iraq War.  In 2004, a Marine in Fallujah was accused of killing a wounded insurgent. However, the facts of that case indicated that his life was in danger. Accordingly, military necessity trumped the other two conditions. He did not kill in cold blood, but responded to a threatened danger in an uncertain environment. That is a far cry from the cases described above.

I firmly believe that American soldiers should carefully adhere to the laws of war, even when they engage a savage enemy — as they have in our recent wars. While it may sound strange to some, I believe the idea of restraint in war helps to civilize a brutal human activity and to limit the descent of soldiers into barbarism. But prudence dictates that we make a distinction between killing a prisoner in cold blood, and protecting oneself and one’s brethren. The president’s pardon obscures this critical distinction, to the detriment of the American military profession.