You are making a lot of assumptions, which Greenwald actually addresses and refutes at the beginning of the article. The targets are often not combatants; in fact, many of the targets have no known identity at all. If anybody strains to minimize civilian casualties, they're doing a piss-poor job of it. In fact, often it looks as if non-combatants and civilian structures were deliberately targeted.
But you are of course right. As long as you a priori define allied action as legitimate military strikes, and enemy action as illegal terror attacks, you will always be right. And that is the very point of the article.
Let's agree to disagree on that one. Because the discussion we should be having is, what objectives is the "War on Terror", (or, as I like to call it, because terrorism is just a method of warfare, War on War) trying to achieve, and are they worth the price?