Palestinian men look at what used to be a tunnel leading from the Gaza Strip into Israel, in the area of Rafah in the southern Gaza Strip, on Aug. 5, 2014, after a 72-hour truce agreed by Israel and Hamas went into effect. (Abed Rahim Khatib/Flash90)

Smoke rises following an Israeli air strike in the Nusseirat in the central Gaza Strip on November 14, 2012. An Israeli strike that killed Hamas's top commander, Ahmed Al-Jaabari, in Gaza is only "the beginning" of an operation to target militant groups...