Netanyahu is in a box. After hinting for months that he would attack Iran if the Obama administration didn’t do more to stop its uranium enrichment, he now seems unable to marshal enough domestic support for military action. The setback could be temporary. His critics appear to be opposed more to the idea of disobeying Washington than going to war over Iranian nukes. (Some are deeply troubled by the public bickering between Washington and Jerusalem in recent weeks.) But the sheer scope of resistance at home—by members of the public; the military’s senior echelon; and now, apparently, Netanyahu’s defense minister, Ehud Barak—seems for the time being, at least, too vast to overcome.

Barak’s shift marks the most significant change over the past few weeks. For much of the summer the defense chief had been Israel’s most aggressive proponent of quick military action. “Barak is even more hawkish than Netanyahu on this issue,” a former official who witnessed his decision making from up close told me in June. The source said Barak liked to tell people how, in the 1990s, he heard top American leaders pledge repeatedly to Israel that Washington would prevent Pakistan from crossing the nuclear threshold. When Islamabad did eventually break out, testing its first nuclear devices in 1998, the Clinton administration condemned the action and then went about quietly adjusting itself to the new reality in South Asia. The lesson Barak absorbed, according to the former official: even ironclad American assurances are never truly ironclad…

Without support from Barak, who was an army general and one of Israel’s most decorated soldiers before turning to politics, it’s almost impossible to imagine Netanyahu undertaking an attack.