The nuclear negotiations with Iran are in their eleventh hour. By Monday we'll know whether a resolution has been reached or a new crisis of the first order added to the conflagrations in the Middle East -- indeed, one that will exacerbate all the others. Even an understanding that lays out a few principles while extending the deadline would be a dangerous outcome. The technical issues are complicated. But they are not in themselves the main obstacles to be overcome. Let's get down to brass tacks. The starbursts of commentary on centrifuge numbers and Iran's retention of low-enriched uranium (LEU), albeit under international inspection, should not be allowed to conceal the underlying reality: If Washington and Tehran want a nuclear deal, it is there for the taking. While the responsibility is shared, the crucial decision rests with the White House. This is not the way that President Obama and his advisers see it, though.