Notice that he did say that war would exist from that time forward, but rather that war had existed, without any declaration. since the attack by the enemy.
Congress took "judicial notice" of the event, but the war was "legally" operational from all times after the attack by the enemy. In addition, since Al Queda has declared war on us, and attacked, all action by Congress is moot.
Well not quite, they still have to authorise and appropriate the necessary funds, if any are required beyond those already appropriated and authorised that is. Congress has done so in this case. We ARE at war.
As I read what seems to be the prevalent interpretation, if we are attacked we are at war. It's only if some nations acts against us in a non violent manner that none the less is a cause belli, a blockade perhaps, that Congress needs to Declare War.
Interesting how we've all been brainwashed since the Korean War at least into thinking we could not be at war unless Congress declared us to be. Kinda changes the notion that Treason is only a crime if Congress has declared war, now doesn't it? Hanoi Jane, et. al., are you reading this?