Personally, I think the President has the inherent constitutional power to do this irrespective what some statute might say. Congress can't restrict the President's constitutional power to defend the US from attack.
Also, he has the "responsibility" to defend the U.S.
Bush has acted responsibly, unlike Klinton.
Uh, no, he's subject to the law. There's nothing in the Constitution that gives him the power to disregard it.