Is the Libyan Armed Action a Constitutionally "legal" war?

from Discussion of the 60-day absence of Congressional authorization of Obama's acts in March 2011:

www.nytimes.com/

The War Powers Resolution of 1973 says that a president must terminate military operations 60 days after notifying Congress that he had introduced armed forces into actual or imminent hostilities. The Libyan operation reached that deadline on Friday.

But Pentagon and military officials said the United States’ participation in the Libyan mission was going forward unchanged. That includes the intermittent use of armed Predator drones to fire missiles at Libyan government forces, as happened on Thursday and Friday, they said.
“We will not halt our current operations, which are limited and in support of this critical, NATO-led humanitarian operation,” said Tommy Vietor, a National Security Council spokesman.
While the legal debate was playing out, NATO commanders seemed to go beyond their typically cautious statements on the conflict, saying that allied airstrikes had prevented Colonel Qaddafi’s forces from making sustained attacks on rebel fighters and had driven the Libyan leader into hiding.
“NATO nations and partners agree we have taken the initiative; we have the momentum,” the alliance spokeswoman, Carmen Romero, said at a Friday news briefing, summarizing the view of NATO ambassadors who met earlier in the week.
A NATO military spokesman, Wing Commander Mike Bracken, said of Colonel Qaddafi: “Effectively he has gone into hiding.”
The briefing on Friday echoed the generally upbeat conclusions contained in a confidential assessment of the operation’s first 60 days that Lt. Gen. Charles Bouchard of Canada, the allied operational commander in Naples, Italy, sent to NATO political and military leaders in Brussels this week, a NATO diplomat said.
While noting the alliance’s steady progress in eroding the combat effectiveness of Colonel Qaddafi’s forces, General Bouchard also outlined three options for how NATO could continue the mission beyond the three months that allied leaders approved in March, said the diplomat, who had been briefed on the report.
One would maintain current NATO force levels. Another option, assuming Colonel Qaddafi was ousted from power, calls for much lower force levels during what could be a transition to a new government. A third plan would increase pressure on Colonel Qaddafi’s government, but does not go into details.
General Bouchard made no recommendations, the diplomat said, leaving that decision to NATO ambassadors.
Late on Friday, the White House released a letter from President Obama to Congressional leaders defending the Libya operation. While he did not directly ask for a resolution authorizing the action or concede that it was necessary, he expressed support for the idea of a legislative endorsement.
“Congressional action in support of the mission would underline the U.S. commitment to this remarkable international effort,” he wrote. “Such a resolution is also important in the context of our constitutional framework, as it would demonstrate a unity of purpose among the political branches on this important national security matter.”
While Congressional leaders have signaled little institutional interest in enforcing the resolution, there are signs that a political controversy is starting to pick up.
On Wednesday, six Republican senators sent a letter to Mr. Obama noting the imminent deadline “for you to terminate the use of the United States armed forces in Libya.” They asked “whether you intend to comply with the requirements of the War Powers Resolution.”
On Thursday, Representative Howard P. McKeon of California, the Republican chairman of the House Armed Services Committee, sent a similar letter to Mr. Obama stressing that the country was about to reach the War Powers Resolution deadline, which he portrayed as a “critical juncture.”
And on Friday, the American Civil Liberties Union also wrote to Mr. Obama expressing its “profound concern” that he was about to violate the War Powers Resolution, and arguing that he had no legal authority to use military force in Libya.
Administration officials offered no theory for why continuing the air war in Libya in the absence of Congressional authorization and beyond the deadline would be lawful.