"Before Libya, the OLC [Office of Legal Counsel] produced an opinion letter about why it was that the president had constitutional authority to attack Libya in the way that it did," Prakash said on the call, which was sponsored by The Federalist Society.

"And it seemed to have the view that the declare war clause [of the Constitution] was a constraint on the president's power to wage war, but that the hostilities in Libya didn't amount to a war because of the duration, the chance of casualties, etc.," said Prakesh, who clerked for Supreme Court Justice Clarence Thomas from 1994 to 1995.

He called this interpretation "somewhat silly," and said it makes no sense to say that "engaging in months-long bombing campaign is not a war within the declare war clause."

"Having said that, I'm sure they're going to rely upon that justification again should they decide to wage war against Syria," he added.

Prakesh's point of view is in line with that of dozens of members of Congress, who wrote a letter to Obama arguing that the Office of Legal Counsel downwardly defined the military's actions in Libya in order to argue it did not need congressional permission. That same letter said Obama needs to get Congress's permission before undertaking any action in Syria.

John Yoo, professor of law at the University of California Berkeley School of Law, agreed with Prakesh on the same teleconference.

"We can all agree that the Obama administration has been utterly incorrect on both the statutory reading of the War Powers Resolution and, to me, the declare war clause," said Yoo, who was deputy U.S. attorney general under the Bush administration.

"To claim that the word 'war' as it's used in the War Powers Resolution or in the Constitution is not triggered or involved when the United States bombs another country, because war is not involved when the other party can't shoot back, I think is just kind of silly," he added. "The one-sidedness of a conflict doesn't determine whether it's war or not."

Yoo also agreed with many members of Congress who believe Obama cannot legally use the War Powers Resolution to justify attacks against Syria because of a national emergency.

The War Powers Resolution does allow the president to use the military to respond to a "national emergency created by an attack upon the United States, its territories or possessions, or its armed forces." But Yoo said that line has not yet been crossed.

"I don't see how anything in Syria so far would qualify for the national emergency created by an attack upon the United States, possessions or its armed forces," he said.

Some have hinted that the administration could justify an attack based on a national emergency because of chemical weapons in Syria that could be used someday against the United States. But Yoo said that would be using a "very broad definition" of the national emergency language in the WPR.

Still, he said the administration could well use these altered definitions of "war" and "national emergency" to justify action.

"What's going to happen with the president is that they're going to have to really contort the language of the War Powers Resolution," he said. "They're really going to have to contort the meaning of the word 'war,' so it doesn't mean situations where we really beat the hell out of someone so bad they can't fire back."