The U.S. Constitution gives Congress the exclusive power to declare war. It’s done so only 11 times since 1798, but U.S. armed forces have been sent into battle abroad hundreds of times. Presidents cite unconventional threats and the need for flexibility and speed to justify deploying the military without prior congressional approval -- the latest example being the Jan. 3 airstrike ordered by President Donald Trump that killed one of Iran’s most powerful generals. Congress is once again trying to reassert its constitutional role in making war. Previous efforts haven’t accomplished much.

1. How has Congress tried to reassert itself?

Misgivings over the Vietnam War, which Congress never officially declared, resulted in the War Powers Act of 1973. Congress enacted the law by overriding a veto by President Richard Nixon, who called it an unconstitutional restriction on the president’s role as commander-in-chief. Under that law, the president must notify Congress within 48 hours of committing armed forces to military action, and those forces must be withdrawn within 60 or 90 days (depending on circumstances) unless authorized by votes in Congress.

2. Did the War Powers Act put Congress in charge of warmaking?

No, because no president has recognized the act’s legal validity. Moreover, Congress has explicitly granted the president a free hand in the biggest military confrontations of the last two decades. The U.S. response to the terrorist attacks of Sept. 11, 2001, were conducted under a law known as the Authorization for the Use of Military Force, or AUMF. Via a second AUMF, passed in 2002, Congress authorized the president to take military action against Iraq. Even so, the last three presidents -- George W. Bush, Barack Obama and now Trump -- have refrained from acknowledging those authorizations as legally binding on their commander-in-chief powers.

3. Is the War Powers Act useless, then?

Given the penchant of presidents to ignore its letter or spirit, some in Congress have tried to enforce or overhaul the four-decade-old law. After President Bill Clinton committed U.S. military forces to Yugoslavia in 1999, 26 members of Congress challenged his legal authority to do so. Their lawsuit was dismissed in court. Over the years, members of Congress have proposed various ways to replace or improve the law. Ideas have included cutting off all funding to any military action that skirts the law’s requirements; repealing the law and creating a joint congressional committee that would consult closely with the president about military operations; and amending the law to eliminate the requirements of an automatic withdrawal after 60 or 90 days, which is a big reason presidents have refused to recognize and abide by the law.

4. Did Trump have congressional approval for the Jan. 3 strike?

No, and Trump said in mid-2019 that he didn’t need approval from Congress to initiate military action against Iran. The day after the airstrike on vehicles near Baghdad’s airport that killed General Qassem Soleimani, the head of Iran’s Al Quds force, the White House sent Congress the formal notification required by the War Powers Act. Trump’s national security adviser, Robert O’Brien, said the strike was “fully authorized” under the 2002 AUMF regarding Iraq, and Secretary of State Michael Pompeo said the administration had acted in response to the threat of an “imminent attack.” Trump, via Twitter, said his tweets “will serve as notification to the United States Congress that should Iran strike any U.S. person or target, the United States will quickly & fully strike back, & perhaps in a disproportionate manner. Such legal notice is not required, but is given nevertheless!”

5. What role will Congress play on Iran going forward?

The Senate approved a resolution restricting Trump’s ability to take military action against Iran, with eight Republicans joining Democrats to approve a measure that would require express congressional approval before a strike. The resolution was expected to pass the Democratic-led House. But the 55-45 Senate vote fell short of the margin that would be needed to override a Trump veto.

To contact the reporters on this story: Daniel Flatley in Washington at dflatley1@bloomberg.net;John O’Neil in New York at joneil18@bloomberg.net

To contact the editors responsible for this story: Laurence Arnold at larnold4@bloomberg.net, Joe Sobczyk

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