Israel is the only liberal democracy in the Middle East and North Africa. Eight million Israelis are surrounded by some 400 million Muslims in more than 20 states. Almost all of Israel's neighbors are anti-Israeli dictatorships, monarchies or theocracies-- a number of them reduced to a state of terrorist chaos. Given the rise of radical Islam, the huge petrodollar wealth of the Middle East and lopsided demography, how has Israel so far survived? The Jewish state has always depended on three unspoken assumptions for its tenuous existence. First, a democratic, nuclear Israel can deter larger enemies. In the Cold War,...