Let me make this a bit more concrete. In WWII, it was understood when Allied troops entered Berlin, the war in Europe would be over. It was understood that the war in the Pacific would end with the surrender of Japan. Even in the Cold War, it was understood that it would be over with the end of Soviet Communism. In the war on terror, who exactly is going to sign the surrender agreement on behalf of the terrorists? What's the terrorist capital for US troops to overrun? As best as I tell, the war will be over when the President declares the war to be over and given that it is the President who is asking for expanded powers, I see a huge conflict of interest.
Nice try, but you have a few ingredients missing in your 'concrete'.
There were no nukes in hands of the enemy then, there were no jets to be hijacked and flown into cities, there was no well funded radical islam, there were no computers, no cell phones, no internet, no electronic banking system, no satellites, on and on and on.
The world, and thus the threat, has changed my friend. Wake up and smell the coffee.