That's a good point about tolerability. I should have noted that the panel never took up the question of whether it was tolerable for Iran to have nuclear weapons or not. I think it's clear from the exercise, though, that it has to be all or nothing. Even if you do succeed in taking out the program via airstrikes, you're likely to get a more hostile Iran that is even more determined to get nuclear weapons and perhaps use them. So your options are then regime change by force, revolution Ledeen-style (dubious), or accomodation. Not a fun list.