Phillip Carter a key component in closing down Guantanamo Bay resigns this week.

Carter was the defense department official in charge of guiding global policy on moving the terrorism suspects and other detainees out of Guantanamo Bay. He was well known as an activist on the issue before joining the Obama administration, and resigns (apparently without notice) right after Obama’s announcement that the January deadline will be missed for closing Guantanamo.

Many are speculating that Carter is disillusioned with Obama, after his administration has shifted towards some of the same policies Carter fought against during the Bush presidency, but he has not confirmed this.