The only so-called “enemy combatant” jailed in the US has pleaded guilty to conspiring with al-Qaeda. Ali al-Marri has been held in isolation without trial at a naval brig in South Carolina for more than five years. The Obama administration charged him in February to avoid a Supreme Court hearing challenging his indefinite jailing. On Thursday, al-Marri pleaded guilty to a single conspiracy charge carrying a maximum fifteen-year sentence. He could serve half that if he’s given credit for his seven-and-a-half-year imprisonment. As part of the agreement, al-Marri admitted to attending militant training camps and traveling to the US under the direction of al-Qaeda leader Khalid Sheikh Mohammed.