This mindset will not change if Guantanamo closes. At the same time, closing the detention facilities will create numerous headaches quite beyond the security issues raised by dangerous detainees who might escape or serve as a magnet for terrorist attacks in U.S.-based facilities.

One immediate problem, identified by FBI Director Robert Mueller, is the very real possibility that the Guantanamo detainees will recruit more terrorists from among the federal inmate population and continue al Qaeda operations from the inside. Radical Islamists already preach jihad in prisons — this was how the just-arrested New York synagogue bombers were recruited — and criminal gangs have proved that a half-in/half-out management model works.

A longer-term problem is that once Guantanamo is closed the option of holding captured enemy combatants any place overseas will be undermined. Over time, more and more such individuals, including the ones convicted by military commissions, would have to be brought to the U.S., especially as Europe backs away from taking such individuals. Aggregating the world’s worst jihadists on American soil, from which they can never be repatriated, is not a smart way to fight a war.