On Feb. 12, 2008, Imad Mughniyah, Hezbollah’s international operations chief, walked on a quiet nighttime street in Damascus after dinner at a nearby restaurant. Not far away, a team of CIA spotters in the Syrian capital was tracking his movements. As Mughniyah approached a parked SUV, a bomb planted in a spare tire on the back of the vehicle exploded, sending a burst of shrapnel across a tight radius. He was killed instantly. The device was triggered remotely from Tel Aviv by agents with Mossad, the Israeli foreign intelligence service, who were in communication with the operatives on the ground...