The decision to prosecute terrorists like Khalid Sheik Mohammed in U.S. civilian courts comes with risks. The Obama administration has discussed some of the more obvious ones — escape, attack, compromise of U.S. intelligence — but has argued that the government can control or neutralize those risks.

Let’s assume they’re right. The administration still hasn’t acknowledged — let alone provided a plan to deal with — one of the greatest hazards: that terrorists found not guilty or sentenced to a term less than life imprisonment will be released, not to Saudi Arabia or Yemen, but onto the streets of the United States. Because of immigration law and international obligations, hardened jihadists currently at Guantánamo Bay, Cuba, shipped to the United States for trial might be here to stay.