In the wake of President Obama's big speech about restraining the war on terrorism, a member of the House intelligence committee is working on a bill to undo the basic authorities to wage it.

Rep. Adam Schiff (D-Calif.) is preparing a piece of legislation that would "sunset" the 2001 Authorization to Use Military Force (AUMF), a foundational law passed in the days after the 9/11. "The current AUMF is outdated and straining at the edges to justify the use of force outside the war theater," Schiff tells Danger Room.

Repealing the AUMF would be the boldest restriction of presidential war powers since 9/11. Both the Bush and Obama administrations have relied on the document to authorize everything from the warrantless electronic surveillance of American citizens to drone strikes against al-Qaida offshoots that did not exist on 9/11. Getting rid of it is certain to invite fierce opposition from more bellicose members of Congress, who have repeatedly demagogued efforts to roll back any post-9/11 wartime authority, let alone the most important one.

Rep. Barbara Lee (D-Calif.), the only legislator to vote against the authorization in 2001, has long fought unsuccessfully to repeal the AUMF. But Schiff is a moderate, not a firebreathing liberal, and while sunsetting the AUMF is sure to be a big legislative challenge, even conservative legislators like Rand Paul (R-Ky.) are raising fundamental questions about the merits of a never-ending war.

Schiff thinks that the end of the U.S. combat mission in Afghanistan in 2014 ought to occasion the end of the AUMF, and his bill would use the Afghanistan drawdown as a hinge point. He openly admits to being unsure whether Congress should pass a follow-on piece of legislation allowing the president a limited version of his war powers, or what those post-Afghanistan powers might appropriately be.

The U.S.'s counterterrorism "architecture is becoming increasingly unsustainable," Schiff says, "but I have only a less clear idea of what should follow." Schiff, a moderate, is still in the early drafting stage of the bill and doesn't yet have a timeline for introducing it. But the animating idea behind it is that Obama ought to come back to Congress to outline what war powers are necessary, so legislators can go on record blessing or rejecting the next phase of the war on terrorism.

There has only been one previous effort to reexamine the AUMF. Spoiler alert: It failed.

Shortly after the GOP win in the 2010 midterm elections, the incoming chairman of the House Armed Services Committee, Rep. Buck McKeon (R-Calif.), argued that it was time for a new version. Since the short 2001 AUMF only authorizes military action against those responsible for 9/11, McKeon contended, the administration lacked legal authority to combat the contemporary versions of al-Qaida in places like Yemen and East Africa. He noted that only half of his colleagues had served in Congress long enough to ever vote on the open-ended war that two administrations have asked them to support.

The Obama administration wasted little time in telling McKeon's committee it wasn't interested in revisiting the AUMF. The 2001 AUMF was "sufficient to address the existing threats that I've seen," Jeh Johnson, then the Pentagon's senior lawyer, testified in March 2011.

Formally, Johnson didn't really explain how a law that was about avenging 9/11 actually allowed Obama to take military action against, say, al-Shebab. But Johnson didn't make the administration's real reasons for opposing the AUMF explicit. It was worried that congressional Republicans would write a bill expanding presidential authority to attack terrorist groups unrelated to al-Qaida, something that would expand a global war that the administration was internally growing skeptical about.

Obama made that position explicit in his speech at the National Defense University – as well as endorsing, for the first time, the eventual repeal of a law he has relied heavily on throughout his presidency.

"I look forward to engaging Congress and the American people in efforts to refine, and ultimately repeal, the AUMF's mandate," Obama said. "And I will not sign laws designed to expand this mandate further. Our systematic effort to dismantle terrorist organizations must continue. But this war, like all wars, must end."

That's a position that may not sit well with the U.S. military. During a Senate hearing last week, generals from the Joint Staff and senior Pentagon civilians argued that the AUMF was a necessary law that should remain in place – unchanged. The position satisfied neither Democratic and Independent critics who saw it as a blank check for war nor Republican critics who considered it too restrictive to fight 2013-era terrorism.

One of them is McKeon, the first legislator who proposed reexamining the AUMF. Repealing it outright doesn't sit well with him – and probably many other congressional Republicans and some Democrats.

"The chairman is far from convinced that's the direction we need to go," says an aide to McKeon's committee. "We need to reaffirm our authority with respect to those [al-Qaida] affiliated groups." What's more, Obama's willingness to "ultimately repeal" the AUMF runs right smack into his codification of a more limited counterterrorism war lasting for years. At the National Defense University, Obama simultaneously talked about a longer war and removing his own authorities for waging it.

Schiff sees all this tension – on the Hill and within the administration – as an opportunity. "There's probably bipartisan support for the idea that the existing AUMF is ill-suited to the nature of the threats we face now," he says. But there's "probably bipartisan opposition to what would come after," both from the left and right. Schiff thinks that disagreement means a congressional debate about the future of presidential authority against terrorism is overdue. He intends to kickstart one.