An effort in Congress to reconsider the law that authorized America’s global war on terror is picking up steam.

The Authorization for Use of Military Force (AUMF), approved by Congress three days after the Sept. 11, 2001 terror attacks, was just 60 words long and has since been used to justify everything from indefinite detention at Guantanamo Bay to drone strikes in Yemen against terrorist groups that didn’t exist when the twin towers fell.

Now, some lawmakers are ready to take another look at the law.

Senate Majority Leader Harry Reid says it’s time to revisit the AUMF. Reid told BuzzFeed Wednesday, “I think 9/11 is a long time ago, and it’s something that needs to be looked at again. I have no problem with that.”

Virginia Democratic Sen. Tim Kaine gave a speech Wednesday saying the law needed to be revisited, and BuzzFeed reported that he’s working on a proposal with Arizona Republican Sen. John McCain. In the House, California Democratic Rep. Adam Schiff is circulating a proposal to amend this year’s defense bill so as to sunset the AUMF in 2016 – which means Congress would have to periodically decide whether America’s war on terror is over.

Revising the AUMF seems to have broad support. After all, President Barack Obama said last year that “I look forward to engaging Congress and the American people in efforts to refine, and ultimately repeal, the AUMF’s mandate.”

But when people talk about revisiting the 2001 AUMF, they often mean different things.

While civil libertarians and anti-war Democrats want an end to the war on terror, in the past, hawks have tried to alter the AUMF to expand it or to justify current operations, not end it.

Just a week after the death of Osama bin Laden in 2011, House Republicans were revisiting the AUMF – in order to ”address the continuing and evolving threat posed by these groups,” not to end what President George W. Bush called America’s global war on terror. Civil libertarians saw the new language as “declaring a new worldwide war without any limitations by time, geography, or national interest.”

The Obama administration opposed it, saying it wasn’t needed, and the president himself has said he won’t sign into law an expansion of the 2001 AUMF.

But again, those who want to revisit the AUMF don’t necessarily want the Obama administration or future presidents to pursue Al-Qaeda less aggressively, they just want to make sure that aggression has the force of law behind it. Crafting legislation that appears to narrow the 2001 authorization, while in effect expanding it, would not be too difficult.

“Somebody who joins an Al-Qaeda affiliate in 2020, who has an evil design against Montenegro, is subject to the interpretation of the AUMF, we are at war with them, according to the interpretations both by the Bush and Obama administrations,” Kaine said Wednesday. “I don’t think Congress passing that AUMF 9/14/01 believed 13 years later we would still be engaging in war.”

McCain said something similar in an Armed Services Committee hearing last year. “None of us, not one who voted for the AUMF, could have envisioned we were about to give future presidents the authority to fight terrorism as far flung as Yemen and Somalia,” McCain said last May.

But McCain made it clear that he didn’t think the U.S. should simply stop fighting those groups.

“Would it not be helpful to the Department of Defense and the American people if we updated the AUMF to make it more explicitly consistent with the realities today which are dramatically different from what they were on that fateful day in New York and Washington?” McCain asked Michael Sheehan, an assistant secretary of defense in a hearing in May 2013. “It does not need to be repealed, but it is hard for me to understand why you would oppose a revision of the Authorization to Use Military Force in light of the dramatically changed landscape that we have in this war on Muslim extremism and al Qaeda and others.”

Perhaps McCain has changed his mind, but it remains to be seen what he and Kaine come up with.

Revising the 2001 AUMF could mean limiting it. Or it could mean sanctioning the fight against Al-Qaeda and its affiliates as we’ve come to know it, with its open-ended indefinite detention of terror suspects, expansive surveillance powers and secretive use of force abroad.