Now facing a genuinely unprecedented configuration of existential threats, Israel's leaders must decide whether to continue their deliberate nuclear ambiguity policy (the "bomb in the basement") as they consider such urgent and overlapping survival issues as regional nuclear proliferation, Jihadist terror-group intersections with enemy states, rationality or irrationality of state and sub-state adversaries, assassination or "targeted killing," preemption, and the probable effects of a "Cold War II" between Russia and the United States. Israel must develop a strategic posture that will involve...