NEWPORT NEWS — Constitutional law professors Jonathan Turley and John Yoo on Monday offered sharply different opinions on the appropriate use of presidential war power at a forum on the campus of Christopher Newport University.

The pair debated in front of a crowd of more than 400 students and faculty members at CNU's Ferguson Center for Arts.

Yoo, who wrote the Bush Administration's legal guidance for enhanced interrogation techniques — including the use of water boarding — argued the president has broad authority under the Constitution to engage active threats to national security.

Turley, a nationally renowned law professor at George Washington University, argued that presidents need more consultation with Congress and need to seek authorization for all military involvement.

The two law professors framed their debate against the backdrop of the recent military action President Obama announced against the "Islamic State of Iraq and the Levant," sometimes referred to as "ISIL" or "ISIS."

The debate presented an interesting juxtaposition.

Yoo, a former Bush Administration official, has been a frequent Obama critic but supported his policy for attacking the Islamic State. Turley, who said he voted for Obama and backs many of his domestic policies, emerged as the sharper critic of the president's calls for military action.

Yoo, now a professor of law at the Berkeley School of Law at the University of California, said the president needs to be able to act quickly to address imminent threats, saying that history's great presidents have used executive action to protect the country in times of emergency.

These greats reacted to crises "not by turning over political leadership to the other branches," Yoo said. Instead, "they tried to act with decision and speed to protect the nation from a threat."

Yoo said he felt Obama was well within his constitutional authority to issue the military action against the Islamic State. He said Congress had sufficient power to check the president by holding the "power of the purse."

"My view is that the president is the commander-in-chief, and so President Obama can use force to prevent a threat like ISIS (from) getting to a point where it can attack us," Yoo said.

But Turley disagreed, saying he questioned Obama's legal reasoning for attacking the Islamic State.

Turley said Congressional approval for the operation was needed — not just existing authorizations for attacking al-Qaeda and its affiliates that were first sought by President Bush for the War on Terror.

"John and I read the constitutional history very differently," Turley said.

He said this question needs to be answered: "When is that war specifically going to end? Is there going to be a moment where the president is going to announce, 'I'm happy to announce terrorism has been defeated'?"

Turley said he didn't think Congress' ability to fund or defund wars was enough to provide appropriate oversight and replace the constitutional power to declare war.

"Power of the purse is one of the greatest mythologies out there," Turley said. "Congress didn't appropriate any money for Libya. The president ran an entire war — which was quite extensive — off free money."

In response, Yoo said the Founding Fathers wanted the executive branch to have a wide amount of independence on national security — instead of a system where the legislature had control over foreign affairs.

"His criticism is of the institution of the presidency as a whole," Yoo said of Turley. "Under his description of our constitutional system, we could be just as well off if there was no executive branch of the government at all."

CNU's Center For American Studies sponsored the debate in honor of Constitution Day, which is Sept. 17.

"We are hoping to restore some faith in our country that individuals of different positions can both be intelligent and speak at a high level in this country on highly passionate issues," said Elizabeth Kaufer-Busch, associate professor and co-director of the Center for American Studies.

Bogues can be reached by phone at 757-247-4536.