Its conclusion is that it's unlikely that anything short of impeachment--which is itself unlikely, of course--will be ineffective to stop this, or future, wars by imperial decree. I happen to agree, grudgingly, with that conclusion, which calls for me to consider whether this nation is still one that I revere. (I've been pondering this ever since the Gulf of Tonkin Resolution handed LBJ unbridled power to destroy Vietnam, which the executive later used to bomb Cambodia.)
I still admire the process that allows public debate on such issues and that permits lawsuits, however ineffective, to be lodged to test the question. But these don't stop the presidential power to make war from being wielded by a single person. (Imagine Bachmann possessed of such power, or Palin!)
The only effective halt to this exercise of executive arrogance would be for the Supreme Court to declare the war illegal and to enter an order enjoining the president from continuing it. If disobeyed, the Court could send a US Marshal (imagine Tommy Lee Jones in the role) to arrest the president for contempt of court, which would not make even a decent screenplay. However--and this is ironic because of the disrespect I have for the five dwarfs on the Court--the conservatives Alito, Roberts, Scalia, Thomas and (somewhat less so) Kennedy are more likely than the other four to make such a ruling and enter such a decree because of their self-proclaimed "strict construction" of the Constitution. By that time, however, enormous devastation would have been wrought, the very devastation the Constitution was written to restrict.