andrew bacevich served 23 years, some of them in vietnam, before retiring from the army. he's now professor of history and international relations at boston university. just this week, he was at a u.s. army war college symposium on the highly pertinent question, how do we know when a war is over? his book, "the limits of power," was a best-seller and his latest, "washington rules: america's path to permanent war," comes out this summer. andrew bacevich, welcome back to "the journal". >> thank you very much. >> moyers: these civilian casualties that we've been hearing about, they're inevitable in war, right? >> sure they are. but i think that what's particularly important about the incidents that we're reading about, is that they really call into question u.s. strategy. i mean, when general mcchrystal conceived of this counterinsurgency approach in afghanistan, one of the... sort of the core principles is that we would act in ways that would demonstrate our benign intentions. we're supposed to be protecting the population. and when it turns out that u.s. forces are killing