Charles Krauthammer‘s latest column at National Review Online dissects the debate over who — the president or Congress — really holds the power to take the United States to war.

Is the Libya war legal? Under the 1973 War Powers Resolution, it is not. President Obama has exceeded the 90-day period to receive retroactive authorization from Congress.

But things are not so simple. No president should accept — and no president from Nixon on has accepted — the constitutionality of the WPR, passed unilaterally by Congress over a presidential veto. On the other hand, every president should have the constitutional decency to get some congressional approval when he takes the country to war.

The model for such constitutional restraint is — yes, Senator Obama — George W. Bush. Not once but twice (Afghanistan and then Iraq) did Bush seek and receive congressional authorization, as his father did for the Gulf War. On Libya, Obama did nothing of the sort. He claimed exemption from the WPR on the grounds that America is not really engaged in “hostilities” in Libya.

To deploy an excuse so transparently ridiculous isn’t just a show of contempt for Congress and for the intelligence of the American people. It manages additionally to undermine the presidency’s own war-making prerogatives by implicitly conceding that if the Libya war really did involve hostilities, the president would indeed be subject to the WPR.

The worst of all possible worlds: Insult Congress, weaken the presidency. A neat trick.