Is a U.S. Air Strike in Iraq Legal?

As the White House grapples with military options for intervening in Iraq to protect Baghdad from Sunni terrorists, it's also examining how an air strike can be justified under U.S. law.

It's not a question without significance, especially for an administration that likes to say it holds the rule of law above all else (even as it adopts elastic interpretations to suit its ends).

Indeed, despite the U.S. military operating freely in Iraq for eight years during its occupation, a potential strike against forces of the Islamic State of Iraq and Syria and its allies presents a tougher call than it appears.

For one thing, the administration has in no uncertain terms repeatedly declared the conflict in Iraq to be over—and in 2011, the United States effectively pulled out of the country after an agreement to leave a more robust U.S. presence couldn't be reached with the Iraqi government. That means the White House may no longer be able to seek legal cover by invoking the 2002 law passed by Congress that authorized the Iraq invasion.

"It's a bad argument," said Bobby Chesney, an expert on national security law at the University of Texas. "Obviously, the context was for action against the government of Iraq."

Chesney conceded that the law was used for years afterward to justify continued U.S. operations in the country after Saddam Hussein's regime fell, but, he said, "We've been out for years. To go in there and attack ISIS—it's really a fresh fight."

Moreover, the administration has come out in favor of repealing the Iraq Authorization of Military Force—and Obama reiterated last week that he hasn't changed his mind. That makes asserting it now, at best, inconvenient and at worst, highly hypocritical.

The White House could instead invoke the broader 2001 AUMF that authorized U.S. action against al-Qaida in the wake of the 9/11 attacks. The main problem with that? Al-Qaida leader Ayman al-Zawahiri has denounced ISIS for its conduct in Syria, where it has clashed with an al-Qaida backed group.

In addition, Chesney noted, the 9/11 AUMF was intended to warrant preemptive action against threats to the United States—and there has been little evidence that ISIS has America on its mind. The best thing for the administration's legal position, he joked, is if al-Zawahiri issues a press release praising ISIS and hinting at reconciliation.

Part of the problem is that the Obama White House has continually resisted suggestions to have Congress rewrite the 9/11 AUMF to embrace a larger swath of terrorist groups, including ones like ISIS, because of concerns over endorsing a perpetual, open-ended war on terrorism.

The question of legal authority for military action is an issue that has dogged this administration time and again. And Obama has done himself no favors with seemingly inconsistent approaches toward the civil wars in Libya and Syria that allow critics to charge that his foreign policy lacks coherence.

In Libya, the White House reasoned that the president had all the constitutional authority he needed to marshal U.S. military assets to help bring down the Qaddafi regime. But last year, when it came to responding to the use of chemical weapons in Syria, Obama ultimately punted and sought congressional approval from Congress for a strike that never came.

While it's almost certain the White House won't let legal obstacles stand in the way of any strategic decision to attack the Sunni insurgents bearing down on Baghdad, this is an administration that has reason to be sensitive to cries of executive overreach. It was just weeks ago, after all, that Obama was accused of bypassing federal law by failing to notify Congress in advance of the prisoner exchange that retrieved Army Sgt. Bowe Bergdahl from the Taliban in Afghanistan.

Still, Obama may end up doing what Republicans like least, falling back on executive authority inherent in the Constitution to justify unilateral military action, as he did in Libya in 2011. In that case, he had the backing of a United Nations resolution and support from NATO. Even so, members of Congress howled after the administration refused to seek authorization in line with the 1973 War Powers Act.

White House lawyers asserted then that the limited role played by U.S. forces in Libya meant the act's requirements weren't triggered. "U.S. operations do not involve sustained fighting or active exchanges of fire with hostile forces, nor do they involve U.S. ground troops," it reasoned in a memo to Congress. It's entirely possible the same rationale will be applied to an Iraqi air strike.

So far, the White House is checking the boxes. Monday evening, as called for by the War Powers Act, it notified Congress of the deployment of almost 300 troops to help protect U.S. personnel in Iraq. But it seems unlikely Obama will seek any sort of formal approval from lawmakers before engaging ISIS—even though, at present, the administration appears to be pursuing diplomatic solutions to the crisis.

"When he spoke on the South Lawn last week, the president made clear we will consult closely with Congress on Iraq as we make determinations about appropriate action," said Caitlin Hayden, a spokeswoman for the National Security Council. "He has not made a decision to undertake military action at this stage, so I'm not going to get ahead of the process and discuss what legal authorities might go along with any hypothetical military action."

The Syria experience may have convinced the administration to fall back on the same legal rationale used in Libya—that this would be only a slight flexing of U.S. military muscle. Republicans who right now are calling for an aggressive response likely will get on board.

But beyond that, should things escalate on the ground, the conversation begins to the get trickier. And the echoes of the Iraq War debate in Washington 12 years ago will stir anew.