It’s clear what the diplomacy around such a comprehensive proposal would entail: We would offer Iran a civil nuclear power capability—and if they reject the proposal, it would be presented to the public as a declaration that the Iranians want a nuclear weapons capability not civil nuclear power. Abandoning incremental step-by-step negotiations for a more direct end-state proposal of this sort offers obvious and not-so-obvious diplomatic advantages. First, the Israelis are much more likely to hold off if they know that this is the aim of the talks. Determining the end-state of Iran’s nuclear program matters much more to them than stopping the clock temporarily, particularly because they fear the price for producing the latter would be the easing of pressure on Iran.
Second, and more importantly, we need a credible basis for using force if it comes to it. Context matters. It matters because the use of force is a means not an end. Iran has the know-how and the engineering capability to reconstitute its nuclear program, so it will be critical to maintain sanctions even after force has been used—and that requires that much of the international community accepts that the use of force was justified. If we or the Israelis use force, it is essential that we be seen as first having tried everything short of force and that the Iranians effectively brought this on themselves.
The point is that we can only demonstrate that diplomacy was tried and failed—that we and/or the Israelis were left with no choice but to use force—if we first directly offer to Iran the possibility of a civilian nuclear program.