A growing number of lawmakers say it's time to revamp or scrap the decade-old law that has guided the war on terror since the attacks of 2001.
"I just don’t want to prejudge the outcome of this thing. I just want to go through the process," Levin told The Hill of his decision to call the hearing.
Sen. Saxby ChamblissSaxby ChamblissGOP hopefuls crowd Georgia special race Democrats go for broke in race for Tom Price's seat Spicer: Trump will 'help the team' if needed in Georgia special election MORE (R-Ga.), a member of Levin’s committee, said it’s important for senators to subject the law to fresh scrutiny.
"I don’t know that there are any changes that just jump out at you, but it does merit constant review because it’s such a critical document with respect to the way that we operate militarily on such a wide front," Chambliss said.
Passed in the days immediately after the 9/11 attacks, the authorization law gave military and intelligence agencies wide leeway to pursue al Qaeda.
From the U.S. terror detainee program to armed drone strikes, the rules have allowed American forces to kill most of the terror group’s senior leaders, including Osama bin Laden.
But more than a decade after the law was approved, the war against al Qaeda and other Islamic militant factions across the globe has evolved far beyond what lawmakers say they intended.
The authority justifying the Obama administration's aggressive use of armed drone strikes against suspected terror targets in Pakistan, Yemen and elsewhere "is certainly a liberal interpretation of AUMF," said Sen. John McCainJohn McCainMeghan McCain: Obama 'a dirty capitalist like the rest of us' Top commander: Don't bet on China reining in North Korea Trudeau, Trump speak for second night about US-Canada trade MORE (R-Ariz.).
"It’s clear it’s time we had a careful examination [of the law] ... and what changes need to be made," McCain said. "And changes need to be made."
To that end, McCain said he is strongly considering introducing amendments to the defense spending bill for fiscal 2014 that would change the counterterrorism law.
"It’s something whose time has come.”
Sen. Lindsey GrahamLindsey GrahamTop admiral: North Korea crisis is 'worst I've seen' Comey to testify before Senate Judiciary Committee Overnight Defense: US moving missile defense system to South Korea | Dems want justification for Syria strike | Army pick pushes back against critics of LGBT record MORE (R-S.C.) said the changing face of terror groups like al Qaeda and others requires the United States to adapt.
"I think the war we’re fighting today is not the war [we were] fighting in 2001. Al Qaeda has morphed. It is segmented [and] it's fragmented," Graham said Wednesday.
"I just think we need to broaden the definition" of U.S. counterterrorism operations "and look at who is the enemy and where is the war in 2013."
Levin said he plans to drill down into whether the changes to the law need to be made to address the military-run terror detention program, particularly in the wake of the Boston Marathon bombing.
The political fight over enemy combatants and military detention reignited in the wake of the Boston attack, with Republicans calling for the Obama administration to hold 19-year-old terror suspect Dzhokhar Tsarnaev as an enemy combatant.
At the time, Levin pushed back on that approach, saying that Tsarnaev should not be held in military custody because he has no connection with al Qaeda or its associated forces.
But the Boston case was just one example of the increasingly murky U.S. policy for prosecuting terrorists who attack on American soil, according to Levin.
"It’s a number of issues, and almost every one of those issues has got some real implications and complexities" for how the U.S. handles terror suspects going forward, Levin said Wednesday.
While Thursday's hearing into the laws governing the U.S. war on terror will begin the debate over whether those laws need to be changed, actual change may be months — or years — down the road, according to Levin.
That said, "I hope to make progress on it," Levin said.