A law called the AUMF gives American presidents broad authority to take military action around the world. But some members of Congress say they granted that power for limited circumstances, and want it back.

When a U.S. drone strike killed Iranian military commander Qasem Soleimani, Americans had a lot of questions. One of the most common was: can the president take that kind of action alone, or does Congress have a role too?

The answer is far from clear. The Authorization for Use of Military Force (known by the acronym AUMF), passed by Congress and signed by George W. Bush immediately after the September 11 terrorist attacks, gives presidents expanded powers to take military action on their own. While the White House has not invoked the AUMF as a basis for its strike on Soleimani, it has suggested in the past that the law would justify action against Iran – and that has some members of Congress worried.

Presidents have argued in recent years that the AUMF is a critical tool for fighting terrorism and keeping Americans safe around the globe. Others believe it to be a blank check for endless war. So, what kinds of military force does the AUMF allow? And should Congress take back some of the power it delegated to the president in 2001?

What is the AUMF?
The War Powers Resolution, passed over the veto of President Nixon in 1973, sets limits on the types of military actions a president can take without approval by Congress. The AUMF offers presidents a workaround. Signed into law on September 18, 2001, the AUMF authorizes the president “to use all necessary and appropriate force against those nations, organizations, or persons he determines planned, authorized, committed, or aided the terrorist attacks that occurred on September 11, 2001, or harbored such organizations or persons, in order to prevent any future acts of international terrorism against the United States by such nations, organizations or persons.” The following year, Congress passed a separate AUMF to authorize military force against the regime of Saddam Hussein.

Although the 2001 AUMF was intended to combat the Taliban and al Qaeda, presidents have interpreted it broadly, tapping it to justify all kinds of military action throughout Africa, the Middle East, and South Asia. President Obama (who initially said he wanted to “refine” and “ultimately repeal” the AUMF) used it as the legal basis for fighting ISIS and for taking action in Syria. President Trump followed suit and his administration continues to invoke the AUMF as the U.S. navigates tensions with Iran.

Should Congress Take Back Power?
Does a nearly two-decade-old AUMF justify military action today? Experts and officials have hotly debated this question for years. Some observers argue that global politics have changed significantly since 9/11 – ISIS, for example, did not even exist in 2001 – and if a president wants to take new military action, Congress should replace or update the AUMF.

In 2017, former CIA director David Petraeus told the House Armed Services Committee that the AUMF had been stretched “beyond all recognition”. That authorization was specifically meant to target al Qaeda, he said, and Congress should update it to align with today’s challenges.

Congress has tried repeatedly to pull back on powers it delegated in 2001. The House nearly passed a repeal of the 2001 AUMF in 2017 but ultimately left it in place. Repeal did finally make it through the House last summer, when legislators began to fear that the White House would use the AUMF as justification for going to war with Iran, but the Senate did not approve the measure.

A new war powers resolution introduced in the Senate could curb the president’s ability to engage in hostilities with Iran, though its prospects are unclear. The House passed a similar measure in recent weeks, a non-binding resolution that does not go to the president’s desk and does not carry the force of law. House Speaker Nancy Pelosi argued that she didn’t want to send a bill to the president, saying she would “not have this statement be diminished by whether the president would veto or not.”

Pelosi’s course of action raises an important point about amending or repealing the AUMF: the president can veto any change to current law. Overriding a president’s veto is possible, but is a big hurdle to cross.

With tensions between the U.S. and Iran still simmering, we may see a new law addressing the power of the president to take military action without Congress. The new war powers resolution has support from a majority of senators, but may not be able to survive a veto.

Learn More

One Person Decides: Whether or not the American strike on Qasem Soleimani was legal is a tremendously complicated question, says one scholar. But the bigger issue is this: the president has enormous power to take military action without input from Congress – via Lawfare

Mere Symbolism: Two Democratic representatives explain why they voted against the House war powers resolution. We need to publicly debate a new AUMF, they say, rather than passing toothless measures that detract from the real challenges we face – via The New York Times

Repeal and Replace: Osama bin Laden and the earlier iteration of al Qaeda that carried out 9/11 are gone. New threats to the U.S. have risen. That’s why, says a conservative writer, Congress should replace the 2001 AUMF with something that makes sense today – via The National Review

A Global War: Nearly two decades after 9/11, the Global War on Terrorism continues. Whether through American military bases, counterterrorism training, combat troops, or air strikes, the U.S. has military involvement in 40 percent of the world’s nations — via Smithsonian Magazine

Mission Creep: Presidential reliance on the AUMF has made it far too easy for international tensions to escalate quickly. One writer turns to an Iranian port-a-potty to make her point – via Foreign Policy