WASHINGTON ― It’s been 15 years since Congress gave the president the authority to take military action against any country or person connected to the 9/11 terrorist attacks, at any time, without additional congressional approval.

It was an unprecedented Authorization for Use of Military Force, sweeping in scope and with no expiration date. It also came at a frantic time. The attacks had happened just days earlier, and Americans’ fear and anger were high. People were grieving the loss of loved ones.

The 2001 AUMF was written quickly and runs just 60 words. When it came up in the Senate, not a single senator opposed it. The House passed it by a 420-1 vote. There was next to no debate.

That lone holdout was Rep. Barbara Lee (D-Calif.). Her fear was that Congress was signing a blank check for endless war. Lee’s voice cracked with emotion as she spoke in the House on Sept. 14, 2001, trying to make sense of the devastation even as she explained why she couldn’t support giving a president such unchecked power.

“However difficult this vote may be, some of us must urge the use of restraint,” Lee said. “Our country is in a state of mourning. Some of us must say let’s step back for a moment, let’s just pause and think through the implications of our actions today so that this does not spiral out of control.”

Watch her speech here:

Lee was clearly in the minority when the vote came down that day, but 15 years later, she appears to have been right.

Since the 2001 AUMF took effect, it has been used to justify 37 military actions in 14 countries, as well as indefinite detention of individuals at Guantanamo Bay, Cuba.

President Barack Obama says it covers attacks on Islamic State militants without new authorization. The Islamic State, or ISIS, is an offshoot of al Qaeda, the group behind the 9/11 attacks, the administration argues, so the 2001 AUMF applies. Nearly 5,000 U.S. military personnel are in Iraq and Syria helping to fight ISIS under that authority. Billions of dollars have been spent battling the extremist group without a debate or vote in Congress on the parameters of the war.

Future presidents can unilaterally send in more U.S. troops and launch additional attacks, too, if they make the case there is a connection to al Qaeda.

Lee’s moment of dissent is perhaps her proudest vote to date. She frequently cites it in war-related debates, and on Wednesday, she launched a petition campaign urging Congress to repeal the 2001 AUMF and debate the proper parameters for a new AUMF specific to the war against ISIS. Congress has shown little willingness to take on the issue, but the California Democrat isn’t ready to stop pushing.

“The Constitution is clear: Congress has an obligation to give the American people a voice on matters of war and peace,” Lee said in a statement. “How can we ask our brave men and women in uniform to fight a war that Congress lacks the courage to even debate?”