"Illegal War" Myth Debunked by Court?

I just finished reading the decision in Hamdan v. Rumsfeld (thank you, Michelle Malkin), along with Paul Mirengoff's review at Powerline. As “legalese” sometimes appears a bit murky, I felt a bit better that Paul seemed to take away many of the same the same things that I did (though I must admit I missed a few things on my first reading that only became apparent after reading his comments).

One thing I did find interesting in the opinion that I don't think anyone has mentioned was the importance the court placed on the joint resolution passed by Congress in the wake of Sept. 11, 2001, which authorized the President:

"to use all necessary and appropriate force against those nations, organizations, of persons he determines planned, authorized, committed or aided” the attacks and recognized the President's “authority under the Constitution to take action to deter and prevent acts of international terrorism against the United States."

The Court then goes on to state:

…the joint resolution "went as far toward a declaration of war as it might, and as far or further than Congress went in the Civil War, the Philippine Insurrection, the Boxer Rebellion, the Punitive Expedition against Pancho Villa, the Korean War, the Vietnam War, the invasion of Panama, the Gulf War, and numerous other conflicts."

The Court mentioned the resolution is the context that Hamdan claimed that Bush violated the separation of powers, which the court rejected. But at the same time the Court rejected Hamdan's appeal, wasn't it also rejecting the "illegal war" myth of the far left?

By citing in their decision that the post 9/11 joint resolution "went as far toward a declaration of war as it might, and as far or further than" many other wars in our nations past, the Court validated the legal standing of the Global War on Terror. In so do, doesn't it therefore invalidate the myth perpetrated by the far left that President Bush was fighting an "illegal war?"

Seems like it to me, but I'm open to other interpretations.