Once a war ends, prisoners of war must be released. That's the straightforward logic cited by lawyers for Guantanamo Bay detainees, who insist that once the Afghanistan war ends, there will be no justification for holding alleged Taliban fighters. Last year, The Washington Post explored the same logic in an article that was written with the presumption that President Obama wants to close the prison:

The approaching end of the U.S. war in Afghanistan could help President Obama move toward what he has said he wanted to do since his first day in office: close the U.S. prison at Guantanamo Bay. Blocked by Congress from releasing or transferring many of the remaining 164 detainees and able to try only a small number of them, administration officials are examining whether the withdrawal of U.S. troops at the end of 2014 could open the door for some to challenge the legal authority ... to continue to imprison them.

Of course, it could be that the White House has changed its mind about the merits of closing Gitmo, or doesn't want to deal with the political fallout of releasing detainees. If that were the case, Obama's decision to keep about 10,000 troops in Afghanistan until 2016 may be used to fight any motion-to-release filed by inmates. In that scenario, the end of the war and its legal implications for Taliban prisoners would be a headache for the next president rather than Obama.

Now imagine Hillary Clinton or Marco Rubio in the White House.

On day one, they're reminded that they can continue with the planned withdrawal of all troops from Afghanistan, that doing so will have both benefits and costs ... and that being forced to release Taliban fighters from Gitmo is one possible cost. Would that cause the next president to keep U.S. troops in the country longer?

The Obama administration could try to end this perverse incentive by renewing its efforts to close the prison at Guantanamo. But doing so would require political capital, and I fear that they'd rather kick this down the road to the next president, even though the presumed Democratic frontrunner and most of the likely Republican field is even more inclined to extend the war and keep Gitmo open.