Those who lead Israel's defense establishment often come to consider peace with the Palestinians a necessary condition for the country's security. Being tasked with maintaining the territories Israel has occupied since the Six-Day War in 1967 evidently causes the military and security brass to support political measures that would end the occupation. And yet the government shows no interest in pursuing a permanent settlement.

To appreciate this divide, consider the late Meir Dagan, who served as major general of the Israel Defense Forces (IDF) and then as director of Mossad, Israel's intelligence agency. Several years ago, I sat on a panel at a conference in Jerusalem convened by then-President Shimon Peres. To my right sat Dagan, who had just completed eight years as head of Mossad; to my left sat Dore Gold, a former academic and former Israeli ambassador.

The two men held very different views about how best to guarantee Israel's security, and it is worth recapitulating their respective arguments.