Megan argues that they are inevitable:
...when you choose war, you choose war crimes--and that this is true regardless of why you are choosing the war. You may be going to war for reasons that even the staunchest of libertarians would support, like defending your territory from violent attack. Just the same, if the war grinds on for any length of time, you will get people violating the Geneva Conventions, doing obscene things to enemy soldiers (dead and alive), and launching attacks that would horrify the population if they were watching a third party do them. By the time you're a year or so into it, the public and the soldiers are reacting to the last attack and the mountain of dead, not to who started it. Dresden would have been unthinkable in 1939; by the time it happened, anything was justifiable if it saved Allied soldiers.[...]
The point is, these things are part of the cost of war, not of the cost of "wars started by the Bush administration" or "wars with bad motives" or "wars we don't like".
I'm sorry but this is preposterous, uninformed, ahistorical. The United States has managed to go to war for two centuries without the president authorizing and monitoring the torture of prisoners. The Bush administration's legalization of torture and withdrawal from Geneva is unique in American history. Yes, wars will lead to individuals committing war crimes in the heat of battle. Yes, it carries a horrifying logic. But an advance, pre-meditated decision by the president to engage in war crimes is new and unprecedented. Bush really is uniquely awful as a president in this respect: an indefensible war criminal, who has permanently stained the country he represents and betrayed the soldiers who expect decency and lawfulness in their commander-in-chief.