Some national security heavy hitters are expected to speak this week at the Democratic National Convention in Philadelphia, including former Defense Secretary Leon Panetta.

Panetta, who is scheduled to speak on Wednesday, served as the leader of the Pentagon from July 2011 to February 2013 under President Obama, overlapping with part of Hillary Clinton’s tenure as secretary of state. He was the director of the Central Intelligence Agency during the 2011 raid on Osama bin Laden in Pakistan.