I would hate to have been the company commander faced with the job of telling his or her soldiers that it was ok for a group (of unknown size) of unidentified individuals holed up in a building to fire light machine guns and missles at them (and anybody else they wanted to shoot at) but they were "under siege" and the troops were not allowed to fire back.

The RPG-7 has an effective range of half a kilometer, and can easily destroy a light tank or taxi cab, and the Kalashnikov can kill a soldier or a woman doing her daily marketing anywhere within its effective range of 1.5 kilometers. Of course, any civilian deaths that occurred during the siege would have been attributed to the Americans, anyway.