There is another caveat here. At his confirmation hearings last year, Gates pledged to be independent and to give the president his unvarnished advice. "But," he emphasized, "there is still only one president of the United States, and he will make the final decision."
In other words (and many people make a mistake in neglecting this fact), Bush really is "the decider." Then again, in previous disputes within the administration, especially over decisions on Iraq, the dissenters have caved or been outmaneuvered. This time, on Iran, the leaders of the State Department, the Defense Department, the military command, and now the intelligence community are on public record as downplaying the wisdom of war—and, with today's NIE, disputing the rationale for even considering war.
Skeptics of war have rarely been so legitimized. Vice President Cheney has never been so isolated. If Bush were to order an attack under these circumstances, he would risk a major eruption in the chain of command, even a constitutional crisis, among many other crises. It seems extremely unlikely that even he would do that.