As images of a man being burned alive in a cage flashed across the Internet in February, word spread through the Pentagon that the Islamic State had killed a Jordanian pilot. Over and over, Paul Lewis, the Defense Department official charged with closing Guantanamo, was asked the same question: “Did the pilot have an orange jumpsuit on?”

“And I had to say, ‘Yes, he did,’” Lewis said.

ISIS deliberately dresses its victims in the orange uniform synonymous with the U.S. military prison in Guantanamo Bay, Cuba. Before it immolated Jordanian First Lt. Moaz al-Kasasbeh, the terror group chose the garish costume for the broadcasted beheadings of American journalists and other non-combatants. On Tuesday, ISIS released its latest graphic video, which purports to show 15 Iraqi men being executed in gruesome ways: drowned in a cage, blown up by a close-range rocket-propelled grenade, or beheaded by explosives detonated around their necks. They all wore orange jumpsuits.  

To Lewis and the Obama administration, each person ISIS executes in an orange jumpsuit is a visceral reminder of why the detention facility must be closed — and a barrier to doing so.

ISIS has raised the stakes just as President Barack Obama takes his last, best chance to close Guantanamo.

Carter has reason to be skeptical. McCain may be the GOP’s national-security leader, but on Guantanamo, the Arizona senator stands nearly alone. The Senate passed the National Defense Authorization Act last week with a 71-25 veto-proof majority and will immediately begin conference with the House, where members have tried to kill Obama’s effort. And even as administration officials race to draft the closure plan, Obama has vowed to veto the NDAA for its requirement to submit a plan and other restrictions on executive-branch authority to handle terror-war detainees.

It’s not what happens with Guantanamo but what happens after. Tucked into the debate over closing the prison is a far more important question, one the U.S. has long avoided but ISIS is forcing Obama to confront: What will the U.S. do with the prisoners of a forever war?

No one has a definitive answer, according to interviews with more than 20 current and former officials from the Pentagon, State Department, Congress and White House. The 10 months since the U.S. entered the war against ISIS have given Lewis and other policymakers new urgency. But a legislative freeze on Guantanamo could be on Obama’s desk in weeks, forcing him into an unpopular veto that could expend much of the limited capital left in his last term.

As Adam Smith, D-Wash., ranking member of the House Armed Services Committee, told Defense One, “This is probably the last chance.”

In 2008, candidate Obama pledged to shutter Guantanamo, calculating that it was a greater national security risk open than closed, as did his rival, McCain, and predecessor, President George W. Bush. On his second day, Obama ordered the prison closed within a year. But his own review delivered a sobering conclusion on the number of detainees who could be prosecuted or moved, and Congress has added additional hurdles by barring transfers to the U.S. and funds for a replacement facility on U.S. soil.

Despite lawmakers’ efforts, Obama has transferred 126 detainees to foreign countries, more than half of the 242 he inherited. Today, 116 people remain detained in Guantanamo, of whom 51 have been cleared for transfer.

The Obama administration hasn’t added inmates to Guantanamo, but many fighters and suspected terrorists have been detained in Afghanistan under his watch, “because we had tens of thousands of troops directly engaged with the Taliban and al Qaeda,” Alisa Stack, the Defense Department’s principal director for detainee policy, told Defense One earlier this month.

Obama has expanded the global counterterrorism fight, yet in order to avoid ground wars in the Middle East — and their prisoners – the president is increasingly relying on lethal air strikes, intelligence, special operations and private military contractors. But as the U.S. deepens its war against ISIS, trickling in special operations missions and troops — 3,500 are now authorized to deploy to Iraq — officials are worried new detainees are inevitable.

The first is in U.S. custody. In May, Delta Forces on a night raid in Syria killed a senior ISIS leader and captured his wife, an Iraqi referred to as Umm Sayyaf. It was the first known offensive action by U.S. troops on the ground in Syria. And it unearthed the bigger question behind the Guantanamo debate: Now what?

Stack confirmed the U.S. military is still holding Sayyaf “in a safe location inside Iraq.”

Pentagon officials parroted the National Security Council’s statement following the raid: “We are working to determine an ultimate disposition for the detainee … We are currently debriefing the detainee to obtain intelligence about [ISIS] operations. We are also working to determine any information she may have regarding hostages, including American citizens.”

U.S. combatant commanders are responsible for deciding “kill or capture,” where and how long to detain, and whether a detainee should be interrogated or charged, Stack said. “Detention assessments are on a case-by-case basis, given the unique nature of operations.”

Others use a different term: ad hoc. Sayyaf is the only suspected ISIS member the Defense Department is detaining, but administration officials clearly don’t expect she will be last.

Meanwhile, Marine Corps Gen. John Kelly, the 4-star commander of U.S. Southern Command, which oversees the prison, requested $76 million for a new housing facility at Guantanamo. The White House opposed the request, but the House included it in its version of the NDAA passed last month.

“I’m a commander, I need a barracks … I’m dealing with the situation that I have now,” Kelly told Defense One. But he also said, if ordered, Guantanamo could be closed “overnight.”

“I don’t know what the solution is,” he said. “Clearly, this administration thinks Guantanamo never should have been opened. The previous administration came up with Guantanamo.”

Before assuming his command, Kelly was legislative assistant to the Marine Corps commandant, a 2-star general in Western Iraq, and a senior military assistant to Defense Secretaries Robert Gates and Leon Panetta.

“The one thing I do fear is if you don’t have a place to put detainees that you pick up on the battlefield, the troops as an example understand that it’s better to capture, because the detainees end up being just an absolute wealth of intel. These idiots tend to talk as soon as you get them — you don’t have to do anything to them,” he said. “But, much as we saw a couple times in Iraq, if you’ve got a grab-and-release program” — he paused ominously — “the troops stop grabbing.”

Kelly doesn’t think the U.S. military needs a permanent detention facility. “I don’t think we’re taking any detainees off the battlefield in say, right now, Iraq and Syria.” He dismissed Sayyaf’s case.

“Remember, when we opened Guantanamo, we had no idea this war would be this long,” he said. “Probably in the future, we would essentially have POW camps … when the war’s over you let them go, I guess. Unless you can prosecute them.”

Is that concerning?

He grinned. “I salute every order I’m given — every legal order I’m given.”

While Lewis’s job is closing Guantanamo, Stack is in charge of the future of U.S. detention: “We’re looking at, ‘Okay, closing Guantanamo, and then what’s next?’”

When she first spoke with Defense One in March, she’d been in her job just over six weeks, but she has been involved with Guantanamo from the beginning. From 2002 to 2004, she was Bush’s deputy director of detainee policy at the Pentagon, where her team raced to set the rules for the thousands being taken prisoner in Afghanistan and Iraq. A decade later under Obama, she’s the director.

John Bellinger, legal counsel to Bush and the National Security Council until 2005, said, “Now, it’s very easy to look back and say, ‘Well this has not been a great success for the U.S.’ But at the time, [Guantanamo] was simply an answer to a military problem.”

At its height, Guantanamo held roughly 800 detainees. Bush released 532 before leaving office, but concluded he couldn’t close the prison. The temporary became indefinite.

“There was very much an opinion that the detention activity at Guantanamo would not take very long,” Stack said. “There was also an impression that the war on terrorism wouldn’t take as long as it has.”

“That’s one of the reasons I wanted to come back,” she said. “How does this story end?”

“I would have closed Guantanamo on the first day,” Obama said in March, when asked what he would do if he could start his presidency over. “But the politics of it got tough, and people got scared by the rhetoric around it.... Instead we’ve had to just chip away at it, year after year after year.”

To revamp the effort, in May 2013, Obama placed two envoys at the departments of State and Defense. To manage diplomacy, he picked Clifford Sloan. To address security, Lewis set up shop at the Pentagon. He has worked for more than a decade on Guantanamo, counseling Democrats and Republicans on the House Armed Services Committee and working for Homeland Security Secretary Jeh Johnson, who was then the Pentagon’s top lawyer.

In the next two years, Panetta transferred four detainees. With the envoys, Defense Secretary Chuck Hagel transferred 44, including 27 in the last six weeks before his November resignation.

Obama requires a consensus from the interagency group before ordering any prisoners transferred from Guantanamo, though it’s not legally necessary. The U.S. then monitors former detainees and prevents travel, but efforts are made to socially reintegrate them.

“These arrangements don’t happen overnight,” Lewis told Defense One on June 10. “Our focus is on mitigating any threats. The whole process requires a ton of behind-the-scenes diplomacy and security work.”

Two days later, the Obama administration transferred six Yemeni detainees to Oman, the first under Carter. No prisoners had moved since January.

The response from members of Congress notified before the latest transfer underscores how divided they remain. Sen. Dick Durbin, D-Ill., said the transfers are “a positive step.” In May, Durbin co-authored a letter urging Obama to close the prison before he leaves office. Last week, Durbin said, “Our national security and military leaders have concluded that the risk of keeping Guantanamo open far outweighs the risk of closing it.”

But Claude Chafin, spokesman for House Armed Services Committee Chairman Mac Thornberry, R-Texas, said, “The chairman remains concerned that the president has prioritized emptying GTMO above ensuring that detainees are not able to go back to the fight.”

“We’re getting close,” Lewis said in February. “I’m confident that Gitmo will be closed in this administration.” The plan is to move to other countries as many detainees cleared for transfer as possible before pushing lawmakers to remove the ban on sending any to U.S. “The smaller the number that we want to send to the states, the better,” he said.

“I’m optimistic we can get this done,” Charlie Trumbull, Sloan’s former deputy, now acting envoy at State, told Defense One on June 8. He hinted at the transfers that happened on June 12, and said there would be more in the near future.

The administration’s best chance, the senior defense official said, is to appeal to lawmakers’ sense of statesmanship as Congress considers the NDAA. “‘Here’s what the responsible thing is to do for Gitmo, here’s the plan. Senator McCain, you support this, we need your help. This is LBJ and Everett Dirksen in ’64, the Civil Rights bill,” the official said, referring to Democratic President Lyndon B. Johnson and Republican Sen. Dirksen, from Illinois, unlikely allies who worked to pass that landmark law. “McCain, you’re a statesman; we’ll make you the hero.’”

“And then I think the administration’s going to have to try a horse trade,” the official said. “We’re going to have to give them something.” The something that opponents want is indefinite detention.

The outlines of how to close Guantanamo have existed for a decade. While Obama has said holding detainees indefinitely without charges is anti-American, to convince skeptics administration officials insist the remaining worst offenders who cannot be prosecuted or transferred abroad would be moved to a maximum security facility in the U.S. McCain and others want the military to hold them, and as enemy combatants. “There are people in Guantanamo Bay who cannot and should not be released because they will return to the terrorist fight,” Carter said this week. Joint Chiefs Chairman Gen. Martin Dempsey has said the same.

“I think they ought to get a little bit of a taste of our maximum security prison system,” said Sen. Joe Manchin, D-W.Va., who worked out the compromise with McCain after shifting to support closure.

McCain said if the White House plan gives sufficient security assurances about a U.S. facility, he additionally could make “a very strong financial argument” to House Republicans. Carter, too, said this week it is “very expensive for the Defense Department to operate Gitmo. I would prefer to not have that expense.”

Obama wants Guantanamo closed this legislative term, Lewis said, but time is even shorter than anticipated. The Senate’s approval of the NDAA last week queues up either an unexpectedly early July passage or a vicious cycle of vetoes. McCain argues his requirement for a Guantanamo closure plan is “a very workable proposal" that would make Obama “more inclined to sign the bill.” But he isn’t confident Congress could sustain a veto on the final NDAA.

McCain asked Carter last Thursday about the timeline for the plan: “They said it’s coming soon, check’s in the mail.” The Pentagon now is directing queries on the plan to White House officials, who remain tight-lipped about the draft and how they intend to win votes for it in Congress. The State Department similarly declined requests for comment on its involvement with the plan.

“We appreciate that members, including Senator McCain, have asked us for a plan for closure. We are working with these members to respond to their requests and concerns,” Ned Price, National Security Council spokesman, told Defense One on Wednesday.

“From the White House’s perspective, it’s a choice between bad and worse,” said a senior Republican Senate aide. “They would have to do something big to change the current dynamic … And even then, the odds of the Senate and House moving significantly toward the White House’s position on Gitmo is a long shot.”

Durbin, ranking member on the Senate Appropriations Defense Subcommittee, said he has no doubt McCain’s support for closing the facility is sincere, but so is Republican opposition.

“Pinning the fate of these prisoners on a presidential plan approved by a Republican Congress,” Durbin said last month, “is a virtual guarantee that nothing is going to happen.” 

Sen. Kelly Ayotte, R-N.H., Obama’s most vocal critic on Guantanamo,  said in February Carter doubted the president could break through. “He very realistically said to me, ‘Although I support the president’s plan or view of closing Gitmo, I don’t see how it’s going to happen,’” she said after Carter’s confirmation hearing.

Though Carter publicly voiced those doubts Tuesday, he’s working on that plan. But Ayotte and others are digging in against it, breaking with McCain over what they call Obama’s “catch and release” program to empty the facility. They remain concerned about detainees rejoining the fight with new groups like ISIS.

According to a March report from National Intelligence Director James Clapper, of the 532 detainees transferred under Bush, 21 percent were confirmed to have reengaged in terrorist activities, and 13 percent were suspected of reengagement. But as of January, of the 115 detainees Obama had transferred since 2008, only six — 5 percent — were confirmed to have reengaged, and one was suspected of doing so. Clapper added one suspect to that category after the report’s completion.

Ayotte, Sen. Lindsey Graham, R-S.C., and others seized on it. In February, a U.S. airstrike killed a former Guantanamo detainee who after his return to Afghanistan in 2007 became an ISIS recruiter. Of the eight suspected or confirmed terrorist recidivists under Obama, at least six remain free, according to ODNI. One is dead.

“We’re not naive,” the senior defense official said. “With the world the way it is today, do you want to release somebody from Gitmo unless you’re pretty darn confident? ... If somebody reengages, they do so at their risk."

Intelligence officials such as National Counterterrorism Center Director Nicholas Rasmussen argue that Guantanamo is used to recruit terrorists and therefore threatens national security. “I’m an honest broker,” Lewis said. “I’m a former Marine — I don’t want to put people at risk, I don’t want to put troops at risk. But I honestly believe Gitmo radicalizes people.”

ISIS has referred to Guantanamo in its online English-language magazine, and reportedly waterboarded its hostages. A review of jihadist websites and social media from late 2009 to April 2014, provided to Defense One by the Pentagon, contains seven pages of senior-level members of al-Qaeda or its affiliates invoking Guantanamo. In December 2011, when al Qaeda leader Ayman al-Zawahiri claimed to have kidnapped USAID worker Warren Weinstein, his No. 4 demand was: “The release of all detainees in Guantanamo and American secret prisons.”

A U.S. airstrike inadvertently killed Weinstein in April.

Obama has avoided the question of what to do with accused terrorists captured on the global battlefield by killing instead of detaining them, critics argue, expanding special operations and drone strikes. As Ben Wittes, editor-in-chief of the national security blog Lawfare, put it, “Largely what you’re doing is incinerating people.”

Bellinger, the former Bush official, said, “I think that there’s a good reason why you’ve not seen the Obama administration detaining all but about two people over the last six-and-a-half years, and instead relying on drone strikes … It’s a lot less visible.”

While lawmakers have supported Obama’s expanded use of lethal strikes, some, including Sen. Richard Burr, R-N.C., chairman of the Senate Intelligence Committee, also argue valuable intelligence is being lost.

Stack concedes the point: “When we use force, capturing and deterring are integral to an operation and often preferred to killing.”

When Obama does direct the detention of a combatant, a specialized interagency team called the “High-Value Interrogation Group,” or HIG, is brought in. Obama created the HIG in 2009 “to conduct interrogations in a manner that will strengthen national security consistent with the rule of law,” according to the Department of Justice. The senior defense official said of the HIG: “When these guys are brought in, we get the information we need out of them.”

Going forward, the senior defense official said, “Any time we use force we’re going to have to have the legal authority to detain … we have to have a long-term detention policy that’s credible, sustainable, and legal.”

Wittes put a sharper point on it. “There’s gonna be real hell to pay,” he said. “Eventually, we are going to have major combat operations, and we don’t have answers to the question of where we’re going to put people.” 

Everyone’s looking to Obama for the answer.

“He’s got to lead; not me,” said Graham, who supports closure. “That ship has sailed, the circumstances have changed, the world is blowing up around us. There is no appetite to close Guantanamo Bay.”

“They’ve got to come up with the plan, then present it to us,” McCain said. “That’s how it works.”

The continued reluctance from lawmakers knows no party; Guantanamo remains a hot-button issue for their constituents.

“The ‘Don’t Close Guantanamo’ forces always win, because people don’t look at the Guantanamo detainees and see victims,” Wittes said. “They see terrorists.”

In January 2015, the Pew Research Center found that 43 percent of Americans think closing the Guantanamo detention facility in the next several years is a good idea, versus 49 percent who think it’s a bad idea. But far more Republicans opposed the notion than Democrats supported it.

In May, a Defense One and Government Business Council poll of senior defense workers and troops found only 24 percent supported closing Guantanamo.

But Thornberry said regardless of congressional opposition, “I’m sure the president will be keeping after this right up ‘till his last day.”

And so will Lewis – as he pointed out wryly, it’s in his title. “Gitmo," he said, "is a legacy issue.”