The Israeli government may have seized on the outrageous murders as a pretext for provoking Hamas into a response that would allow Israel, in turn, to invade and destroy the tunnels Hamas has dug from Gaza into Israel. Though Israeli leaders claim to have been surprised by the extent and sophistication of the tunnels they discovered, Israel’s military briefed the government on the tunnels more than a year ago, and the government created a special task force to consider how to deal with them.