Sixteen years after voting for a war on terrorism that turned the world into a global battlefield, the Senate is taking a tentative step at reconsidering the law that authorized that conflict, the 2001 Authorization to Use Military Force. Yet the leading replacement for the AUMF might, in the guise of reasserting congressional power over the war, be even more of a blank check.

Late on Monday afternoon, the secretaries of State and Defense, Rex Tillerson and Jim Mattis, are scheduled to tell the Senate’s foreign relations committee how Donald Trump’s administration views its war powers and their limits under the AUMF.

As recently as August, Tillerson’s State Department informed Congress it thinks the 2001 version is fine—even though that 60-word document, passed in the traumatic days after the 9/11 attacks, long predated the rise of the Islamic State and the al Qaeda offshoots that the U.S. currently targets. And Trump is following in Barack Obama’s footsteps. Obama rested the war on ISIS on the AUMF a year after arguing for “ultimately repeal[ing]” the 2001 legislation.

“It is frankly amazing,” Sen. Bernie Sanders told The Daily Beast, “that the president is using the 2001 AUMF to wage war against a group, ISIS, which did not exist when it was written and passed.”

Few observers, including counterterrorism veterans, consider the 2001 AUMF relevant to the 2017 version of the war on terrorism. It’s not even a partisan issue. In 2011, the Republican chairman of the House Armed Services Committee, Buck McKeon, and his now-successor, Mac Thornberry, urged the Obama administration to work with Congress to pass a new one. Not only did they argue the 2011-era war on terror was materially different from the 2001 version, but they thought Congress was shirking its responsibilities by declining to consider an updated version.

“I think the AUMF has been stretched beyond recognition at this point and we need a new one, and Congress needs to get back into the business of accepting responsibility for armed conflicts,” Jeh Johnson, Obama’s secretary of Homeland Security and senior Pentagon attorney, told The Daily Beast.

Johnson added: “When you’re in office, you can’t say that, because what you’re saying is the military is acting beyond domestic legal authority.”

Tim Kaine, the Virginia Democratic senator, has for years made a similar argument. In May, he and retiring GOP colleague Jeff Flake, both of whom sit on the foreign relations committee, introduced an alternative that is likely to feature substantially in Monday’s hearing with Tillerson and Mattis. Kaine’s urgency stems as well from his belief that Trump particularly can’t be trusted with the 2001 AUMF.

“One of the reasons that I was so hard on President Obama on this use of the 9/11 authorization against ISIS is I said, look, I think this is being stretched far beyond what was originally intended. I generally believe[d] that President Obama will use this broad definition and power in a very careful way,” Kaine told The Daily Beast. “But once you allow it to be stretched to encompass anything, we will have a president who will not use it in a careful way. And I think there’s a lot of us, Democrats and Republicans, who are very worried about this president’s judgment.”

“ When you’re in office, you can’t say that the military is acting beyond domestic legal authority. ” — Jeh Johnson

But while a constituency exists for the threshold question of revisiting the AUMF, there is no consensus for how strictly it should bind the president’s conduct of the war. And there is concern in civil libertarian circles that not only is Kaine’s alternative insufficient, it might inadvertently give Trump even more warfighting power than he presently has.

‘Never-Ending Wars All Around the World’

Sixteen years on, the 2001 AUMF looks less like a temporary grant of sweeping powers to address an immediate crisis than the American equivalent of an Emergency Law familiar in authoritarian countries like Egypt. Its reach has come to include wars against al Qaeda offshoots or affiliates in Yemen (now nearing its ninth year) and Somalia (its 11th). It is the legal predicate for, more recently, the military detention without charge of an unnamed American citizen captured nearly two months ago in Syria allegedly fighting for ISIS. (Coincidentally, the Justice Department on Monday must respond to an ACLU challenge to his detention.)

The Kaine-Flake replacement AUMF explicitly blesses a war against ISIS. It permits the same against “any person or force, other than a sovereign nation” that “is a part of, or substantially supports al-Qaeda, the Taliban, or the Islamic State in Iraq and Syria” and “is engaged in hostilities against the United States, its Armed Forces or other personnel.” Specified are several such groups: Khorasan, the Nusra Front, al Qaeda in the Arabian Peninsula, and al-Shabab.

The text also codifies war in “Afghanistan, Iraq, Syria, Somalia, Libya or Yemen,” but does not restrict the war to those six countries. A president can add a person or group to the list after telling Congress why doing so is “necessary and appropriate.” He or she does not have to provide the objective of military action or a deadline for achieving it. Nor does the bill rule out U.S. citizens or groups on U.S. soil as potential targets.

If Congress has a problem, it will have to formally vote to disapprove a new target. That’s one of the major legislative oversight mechanisms the new AUMF provides. The other is that the AUMF “sunsets” in five years, meaning Congress will have to debate a new one afterward, lest the war powers vanish.

Kaine considers that a reasonable compromise between oversight and executive prerogative: “We put some similar limitation on geography, allowing the administration to list where action is taking place and then putting the burden upon the shoulders of Congress to disapprove if we don’t really feel like that’s warranted. And both of those require a notice not only to us but to the public. And they defer to an executive by having it be subject to a resolution of disapproval rather than approval.”

Some of Kaine’s Democratic counterparts in the House are similarly wary of backing specific curtailments on executive power. Rep. Adam Schiff (D-CA), who has introduced new war authorizations over the last several years including one in April, is pushing for a mechanism that would allow Congress to “modify, revise, or repeal” any president’s decision to deploy ground troops, in addition to a three-year sunset. But he cautioned against blanket prohibitions on ground troops or geographic locations, telling The Daily Beast that he wants to preserve the executive branch’s “flexibility.”

“I certainly am concerned that we carefully weigh the deployment of troops anywhere, even in a counterterror mission,” Schiff said in an interview. “Because you can have mission creep. But I think the better approach is to allow a congressional check rather than, on the front end, trying to define geographically.”

But all this sits uneasily with legislators to Kaine’s and Schiff’s left.

“I have great respect for Jeff and Tim,” said their foreign-relations committee colleague Chris Murphy, a Connecticut Democrat, “and they deserve credit for coming up with the only possibly workably framework. I don’t think their framework goes far enough to protect against executive abuse, but I think they’re close.”

Murphy considers two to three years “a good starting point” for war authorization alongside geographic restrictions on where the war is fought: “I think the question is whether we would continue to allow for very targeted special operations missions and place the limitations on broader deployment of U.S. forces.”

Sanders, who recently termed the war on terrorism a disaster, sounded similar tones without mentioning the Kaine-Flake AUMF specifically.

A new AUMF “must be clear and specific about who we are fighting, the mission objectives, and reporting requirements from the president. It must explicitly affirm U.S. compliance with international law, and include a sunset clause to enable Congress to reexamine the AUMF after several years and decide whether it is still necessary and appropriate,” Sanders said. “The American people do not want to be engaged in never-ending wars all around the world.”

‘The President Could List the U.S. as a Battlefield’

Outside of Congress, criticism of the new AUMF is sharper—prompted by the specific ways the war on terrorism has mutated.

Kaine and Flake’s AUMF does not require a target to be a member of ISIS or any similar group. Even a single “person” can be legally attacked. The AUMF’s threshold for inclusion, “substantially support[ing]” such a listed target, goes undefined, meaning Trump—who has no problem conflating Islam and terrorism—will be in charge of defining who “substantially supports” terrorism. In an era when people who have no actual contact with ISIS shoot up nightclubs in its name, Christopher Anders of the ACLU considers the new bill an even broader grant of authority than the 2001 version.

“One of the major problems with this bill is there is no prohibition on the president’s authorization of military action within the U.S. itself and against U.S. citizens. Under this bill, the president would be able to list the U.S. as a battlefield country and be able to list Americans and American groups as among the enemy,” Anders told The Daily Beast.

And the political dynamic the Kaine-Flake AUMF lays out puts Congress in the position of needing overwhelming opposition to preventing the sprawl of the war on terrorism. “Congress, if it was able to muster a two-thirds majority in both the House and Senate would be able to stop the president from doing that, but that’s a high hurdle,” Anders added, because the president could veto such a legislative “disapproval.” In practice, Congress would have to clear that hurdle in the aftermath of a terrorist attack and over a White House’s argument that its actions are necessary to prevent the next one.

Nor does a sunset actually yield finality. Sunsets are legislators’ favorite Augustinian technique for gesturing at ending controversial security measures instead of ending them. Reauthorizing sunsetting surveillance legislation like the Patriot Act and now the FISA Amendments Act in practice becomes a vehicle for expanding their scope.

Whatever hesitation there is on the left about insufficient prohibitions on a sprawling war are not shared across the aisle. Influential Republicans who agree that it’s past time to replace the AUMF do not see doing so as a mechanism to rein in the war on terrorism.

“Consistent with Article II, you cannot have Congress dictating military tactics. So geographical limitations, all sorts of ideas and limitations not only don’t make sense, hinder our military, but probably are not constitutional,” Thornberry, the House Armed Services Committee chairman, told The Daily Beast. “Time limits, I think you can make a better argument on, although there is another side that you’re telegraphing something to the enemy that you may not want to. All that can be discussed.”

And whatever AUMF debate occurs in the wake of Monday’s testimony—or doesn’t—will unfold as the Pentagon mulls expanding operations in Niger and the Chad River Basin against previously obscure local fighters whom the military ties to ISIS that are responsible for killing four elite U.S. soldiers this month. Murphy warns that acquiescing to or expanding Trump’s military mandate for counterterrorism will not stop there.

“I would be less worried about [Trump’s] plans in North Korea if we were doing our work to constrain his actions in the Middle East and Africa,” Murphy said.

Congressional “silence,” Murphy continued, “suggests he has a blank check from us.”