Abstract

Soldiers sign contracts to obey lawful orders; they also swear oaths to this end. The enlistment contract for the Armed Forces of the United States combines both elements: '9a. My enlistment is more than an employment agreement. As a member of the Armed Forces of the United States, I will be: (1) Required to obey all lawful orders and perform all assigned duties … (4) Required upon order to serve in combat or other hazardous situations.' We standardly think that these oaths and contracts give soldiers new moral reasons to fight. Many also think that soldiers who are ordered to fight by legitimate states have moral reasons to obey those orders, just in virtue of their provenance. We generate these reasons through our voluntary decisions—to sign the contract or swear the oath; to form the institutions and give the orders. They are therefore additional moral reasons, on top of the reasons that we have prior to those voluntary decisions. Simply because they are additional, these reasons seem limited in force and scope. In particular, they arguably cannot override pre-existing commitments. For example, if I already have a duty not to kill an innocent person, my promising to breach that duty seems irrelevant to whether doing so is permissible. Similarly for orders issued by legitimate states: the citizens of a legitimate state have pre-existing moral reasons not to kill the innocent; by what alchemy could their state's orders allow combatants to override those reasons? If additional reasons could make prohibited acts permissible, as Sidgwick observed, ‘we could evade any moral obligation by promising not to fulfil it, which is clearly absurd’ (Sidgwick 1981). We might conclude that the contracts soldiers sign, the oaths they take and the orders they receive have weight only when they pertain to acts that soldiers are already allowed to do. Perhaps these additional reasons can require actions that would otherwise be merely permissible, but they cannot license otherwise prohibited actions. If this is right, then it radically limits the relevance of contracts, oaths and authority to the ethics of war, since almost all conflicts involve soldiers breaching some pre-existing moral duties. This is obviously true for soldiers fighting on the unjust side in a war, since almost all the killing they do is unjust. But in all actual wars soldiers on the just side also kill at least some innocent victims, whether as part of an unjust subordinate aim, as ‘collateral damage’, or simply because their adversaries are not sufficiently responsible for unjustified threats to be liable to be killed. If additional reasons cannot make otherwise prohibited acts permissible, then they are practically irrelevant to the ethics of killing in war, at least in this sense: if fighting is impermissible without regard to the contract, oath and authority of their state, then fighting is simply impermissible. This is a tempting conclusion. In this paper, however, I argue that even if it is true at the level of objective permissibility, it is false for subjective permissibility. And since subjective permissibility is where (at least some of) the action is in the ethics of war, this is a significant result. I explain first why additional reasons can make otherwise subjectively prohibited acts permissible, then why just war theorists should care more than they seem to about subjective permissibility. Although I focus throughout on the ethics of war, my arguments generalise to all kinds of additional reasons.