A former Army commander who designed and implemented counterinsurgency campaigns in Iraq and Afghanistan, Gen. David Petraeus has played as large a role as any in shaping the way the U.S. wages war in the 21st Century. That trend continued in 2012, as Petraeus oversaw the Obama’s Administration expanding targeted drone program from his new post atop the Central Intelligence Agency. But the decorated spy chief proved fallible. After the death of four Americans, including Amb. Chris Stevens, on Sept. 11 in Libya, the press raised questions about apparent security lapses at the CIA-guarded Benghazi outpost. Before Congress called Petraeus to testify, FBI investigators discovered details of a messy extra-marital affair with his biographer. After 5 years as the face of U.S. counterinsurgency and counterterrorism, Petraeus resigned from office Nov. 9.