At the heart of the military profession is the view that soldiers are first and foremost servants of the state. While that may be true, it does not mean we should overlook the fact that soldiers are also moral agents, responsible for their actions. Their contractual obligation to the state does not eliminate their individual moral responsibility to examine the justness of the wars they are ordered to wage. I agree with Jeff McMahan that if soldiers find a war to be unjust, they have a responsibility to not participate in it and to become selective conscientious objectors.

Yet soldiers assume that serving the state comes at the expense of their own moral agency. According to this view, the oath soldiers take trumps all other moral concerns—including the duty not to participate in an unjust war.

This view is not entirely implausible. The very nature of the military, after all, seems to condition soldiers to go to war without attempting to ascertain the war’s justness. Military organizations must be sufficiently disciplined, with a recognized hierarchy of authority, to ensure orders are carried out consistently and reliably, so soldiers are trained to internalize the importance of obedience. As Samuel Huntington puts it in The Soldier and The State (1967), “For the profession to perform its function, each level within it must be able to command the instantaneous and loyal obedience of subordinate levels. Without those relationships, military professionalism is impossible.”

This focus on loyalty and obedience is particularly clear in the oath American soldiers take when they enlist:

I do solemnly swear (or affirm) that I will support and defend the Constitution of the United States against all enemies, foreign and domestic; that I will bear true faith and allegiance to the same; and that I will obey the orders of the President of the United States and the orders of the officers appointed over me, according to regulations and the Uniform Code of Military Justice. So help me God.

But while the weight of the Professional Military Ethic and its associated oaths certainly should not be downplayed, adherence to an ethic or oath should not be viewed as the trump card requiring a soldier to fight in an unjust war.

An oath, no matter how solemn, cannot require someone to carry out a moral wrong. 

An oath, no matter how solemn, cannot require someone to carry out a moral wrong. For example, consider the case of a son who is called to the deathbed of his father. They clasp hands, and the father extracts a solemn oath from his son to carry out his last wishes as laid out in a sealed envelope the father presses in to his son’s hand. The son agrees. A few moments later the father passes away. When the son opens the envelope, he is horrified to discover that his father’s last wishes include hiring a hit man to kill some of his former neighbors and providing money to a terrorist organization. Given what the son is asked to do, it is hard to see how the son could be morally obligated to carry out his father’s wishes. While he took the oath in good faith, his reasonable expectation was that the requests he would be asked to fulfill would not be immoral ones.

Such is the case with soldiers who take oaths. They should expect that following through on their oaths may require fighting on behalf of the state in support of just causes such as self-defense or defense of others. However, there is no reasonable expectation that their oaths require them knowingly and willingly to engage in unjustified harm to

So even though soldiers are servants of the state, they remain autonomous moral agents responsible for their actions, and they should exercise their best judgment when deciding to go to war—regardless of whether they are offered a right of selective conscientious objection. One should not need a special right of selective conscientious objection to do what is morally required.

The best way to promote and facilitate moral deliberation among soldiers is to better educate them about the ethical underpinnings of their profession and the grave moral responsibilities that go with it. While education may not prevent some soldiers from willingly participating in an unjust war, over time it would likely result in cultural change within military institutions and reduce the number who do. Compared to McMahan’s proposal, it would also be less likely to encourage malingering. But, most important, it would remind soldiers that the moral burden falls, in the end, on them.