"Any development that makes war appear to be easier or cheaper is dangerous and morally troubling. It lowers the political threshold of war. It threatens to weaken the moral presumption against the use of armed force." David Cortwright, writing
at CNN.com on drones.
It is a legitimate argument, but its application is wider than may be obvious. The Geneva Conventions, for instance, are designed to make war cheaper—not in dollars but in human costs. The pre-Napoleonic rules of parole, under which a prisoner of war could give his word not to try to escape and then spend his imprisonment in the town inn instead of the much less comfortable prison, or even give his word not to fight until exchanged and then be sent home, were designed to make war less costly.
Any such change has two effects. One is to reduce the cost, the amount of damage to things that matter to human beings, including human beings themselves, of warfare, which is good. The other is to increase the amount of warfare, which is bad. There is no theoretical basis to say, in general, which effect is larger—it depends on the elasticity of supply of war.
In my Law's Order
, I discuss [search for the word "duress" in the chapter]
the same issue in a different context—whether contracts made under duress ought to be enforceable. When the mugger threatens to kill you if you don't pay him a hundred dollars and you pay with a check, should you be free to call up your bank and cancel payment once he is out of sight? Being able to pay him means that when mugged you don't get killed for failure to offer your mugger enough to let you go. But it also means that mugging is more profitable, so more of it happens.
In that particular case, I am pretty sure that making the contract enforceable has, on net, negative consequences. But there is no good reason to suppose that the same is true for innovations, technological or otherwise, that make war less costly.