We're killing too few bad guys for resources spent.—of course, bystanders aside (and Allah only knows how many of those have been toted up as "terrorist" kills), a significant fraction of the "bad guys" foolishly imagine that they're fighting on behalf of their country to expel a foreign invader. We know, of course, that the Great White Father in Washington wants nothing but good for all the peace-loving people of Wogistania, but you can understand how a buncha ignorant furriners might not see the Big Picture.
cordially,