What is "legislative fiat"? "Fiat" is not used that way; this is practically an oxymoron. Do you mean by act of Congress (i.e. legislation)? Uh, Congress most certainly can delegate to the President the authority for military action by passing legislation. In fact that is their Constitutional function, and that is precisely what they did, as the original poster has documented.
Of course personally, I am a whole lot more concerned about the so called USA PATRIOT ACT, Homeland Security Act, and the currently named USA PATRIOT ACT 2 than I am Saddam Hussein or Bin Laden
Of course you are.