Retired Gen. David Petraeus discusses tensions between the U.S. and Iran, reflects on his 37 years in the U.S. Army, leading troop surges in Iraq and Afghanistan, and American involvement in both countries.

Lt. Gen. H.R. McMaster responds to the suicide attack that killed at least 13 U.S. service members outside the Kabul airport; Gen. David Petraeus discusses the U.S. withdrawal from Afghanistan and what Taliban rule means for American security.