While one can debate the degree to which the presidency is imperial, it’s simply untrue that the war in Libya is illegal in any shape, manner, or form. It’s being conducted under the auspices of both the UN Charter and the North Atlantic Treaty, which rather covers it internationally. ~James Joyner

As far as the North Atlantic Treaty goes, this is false. The North Atlantic Treaty has nothing to do with what is taking place in Libya. The war is not being fought to fulfill obligations under that treaty, and NATO is not participating in the Libyan war because of the treaty. Indeed, there is no way that a treaty that created a defensive alliance could be used to authorize an attack on a state that did not attack any member of the alliance. At best, NATO is acting as the institution through which member governments are enforcing a Security Council resolution.

As far as U.S. law is concerned, this is also wrong. The President has no authority under the Constitution to do what Obama has done in Libya. The Libyan war doesn’t even have the ridiculous Clinton administration excuse of “implicit authorization” through a vote for funding the war, and to this day the Libyan war continues to be funded out of the Pentagon’s current budget. The Constitution did not vest the President with the power to start a war against another state (or anyone else) on his authority. This is the very sort of arbitrary war that the Framers sought to avoid. War powers were not ambiguously divided. They were very clearly divided. Since WWII and especially since Korea, the divisions have been blurred by executive usurpation and Congressional surrender, and members of both parties have been happy to collaborate in this blurring when the executive was under their party’s control. The fact that Congress has completely failed to check the executive in this matter doesn’t make Obama’s actions legal. It just means that there will apparently be no attempt to hold him accountable for his illegal war.

Contra Andrew, the war was illegal from the start. There wasn’t a time in March when it was legal, but then became illegal later. Obama has abused the authority given to him as Commander-in-Chief. It doesn’t cease to be an abuse of power because Congress and the public are indifferent. What that means is that Obama will evidently get away with his illegal actions.