Today, the United States and Afghanistan signed a long-awaited bilateral security agreement. The U.S. government promised to withdraw combat troops by December, and to leave nearly 10,000 U.S. troops plus allied forces in the country in an “advise-and-assist mission” after combat forces withdraw at the end of this year.

Afghanistan’s new president, Ashraf Ghani, signed the agreement after his predecessor Hamid Karzai, refused to sign one in 2013. The hope is that the U.S. presence will help ensure Afghanistan’s government does not fall victim to Iraq-like sectarian chaos. But as for where and how the U.S. combats terrorism going forward, the deal — which remains largely secret — raises at least as many questions as it answers.

For example, what will happen to several dozen prisoners the United States still holds at the Parwan detention facility (formerly known as Bagram) outside Kabul?  The U.S. formally turned over management of the facility to Afghanistan last year, but retained control over its non-Afghan detainees. Although the United States has refused to disclose their identities, U.S. officials have unofficially revealed that most are Pakistani. Others are believed to be from Yemen, Russia and Saudi Arabia. Many have been imprisoned by the United States without charge or trial for over a decade.

U.S. Brigadier General Patrick J. Reinert recently told Reuters that the United States may send some back to their home countries, may bring some to the United States, and may even send some to Guantanamo Bay. But adding to the population at the Guantanamo prison, which President Obama has been promising to close since he first took office, would be a huge mistake. (Instead, here’s how the U.S. can close it.)

Indeed, it’s not even clear what legal authority the United States will have to maintain the detention center at Guantanamo after it withdraws combat troops from Afghanistan. The withdrawal of combat troops suggests the war is at an end. The armed conflict against the Taliban and al Qaeda in Afghanistan was the alleged legal basis for the Guantanamo prison when the United States created it. Will that war be over by January 1? And doesn’t that mean the Guantanamo prisoners will have to be released? Surely many of those detainees and their lawyers will make that argument.

The Obama Administration is likely to claim that even if the war against the Taliban in Afghanistan is over, the war against al Qaeda and “associated forces” continues. “Associated forces” is a term the administration has used to expand the war beyond its initial targets, and which the courts have sanctioned in cases brought by Guantanamo detainees seeking their freedom. But as many of us have lamented repeatedly, the administration has never defined or named those “associated forces”, which risks creating and perpetuating a war with no end. Especially when you’re talking about terrorist organizations, there will always be a new “associated force” you can add to your target list. The administration seems to be doing that now even with ISIS, or ISIL, which has publicly and officially broken its ties with al Qaeda. If that group can be lumped in with “associated forces”, then the list of potential enemies seems endless.

Still, the withdrawal of combat troops from Afghanistan by the end of this year signifies something. The Obama administration will no doubt herald it as a major accomplishment and part of the president’s peacemaking legacy. For that to be credible, the Administration needs to state more clearly what exactly this means for its broader counter-terrorism vision.

If troop withdrawal is a first step toward ending a 13-year conflict, what’s the next step? And when will the conflict actually end? If the threats have changed and new terrorist groups have emerged, just how much of a threat do they really pose to the United States? Is the threat serious enough to require U.S. military force to fight it? If so, Congress and the American public should be debating that. It can’t just be up to the commander in chief to end one war and a start a new one on his own, claiming they’re all part of one big scary whole.

If the withdrawal of U.S. ground troops from Afghanistan and creation of a security agreement there means anything, then it must mean at the very least that it’s time for a public discussion and debate back home about where we go from here.