Iraqi illegality?

Bruce Ackerman co-wrote this piece at AlterNet, pointing out that Iraq War II has been illegal since the beginning of the year:

The Bush administration's infatuation with presidential power has finally pushed the country over a constitutional precipice. As of New Year's Day, ongoing combat in Iraq is illegal under US law. In authorizing an invasion in 2002, Congress did not give President Bush a blank check. It explicitly limited the use of force to two purposes: to "defend the national security of the US from the threat posed by Iraq" and "enforce all relevant UN Security Council resolutions."

Five years after the fall of Saddam Hussein, the government of Iraq no longer poses a threat. Our continuing intervention has been based on the second clause of Congress' grant of war-making power. Coalition troops have been acting under a series of Security Council resolutions authorizing the continuing occupation of Iraq. But this year, Bush allowed the UN mandate to expire on December 31 without requesting a renewal. At precisely one second after midnight, Congress' authorization of the war expired along with this mandate.

Although the immediate withdrawal of our troops may seem to be the clean-slate option for an incoming administration alleged by some to be radical, Ackerman suggests that "President Obama should submit the Bush-Maliki agreement to Congress on January 20 and urge its speedy approval:"

This request is likely to win broad bipartisan support. Rapid congressional ratification will not only fill the legal vacuum threatening the constitutional integrity of our military operations in Iraq. Together with the closing of Guantanamo, it will show that Obama is serious about reining in the worst presidentialist abuses of the Bush years.