Sullivan gets a bit peeved at Megan McArdle. He seems to think THIS post argues that the Administration's authorization or implicit knowledge of torture, Gitmo, Abu Ghraib, etc. is fine b/c it is inevitable.
Now, I could be wrong, but I believe Megan is making more of an uber-academic point here. Look, in any war or "military conflict" war crimes, mostly on the battlefield, ARE inevitable. No matter what safeguards are in place, it is inevitable that a few rogues will commit atrocities. So, yes, when one chooses or is forced into war, you are, in a way, choosing war crimes.
I don't think she's excusing THIS, which is far outside the scope of "normal" crimes. That said, she's not exactly crystal clear on this, but that's my interpretation.