Being the fair-minded individual that I am, sort of, I spent a few minutes trying to read up on some of the arguments against a grand bargain with Iran. (Like I said, I think incremental engagement of the sort advocated by the Council of Foreign Relations Task Force Report would be a better option, but let's go with a grand bargain for now.)

Tom Donnelly of AEI hates it because it reminds him too much of the 1994 Agreed Framework with North Korea. But as those who were there will tell you, the United States welched on the Framework long before North Korea did. As soon as Kim Jong Il started getting jittery about those "security assurances," he decided -- like any rational leader would do -- to opt for nukes. But by all accounts, the Agreed Framework was more or less the right idea.

So much for that. Henry Skolski's concerns are much more substantial. First, he sensibly notes that the Non-Proliferation Treaty should more state clearly that enrichment and reprocessing are out of bounds. Kerry should also recognize this. Second, light water reactors present real security risks, and nations can easily divert fresh fuel to make nuclear weapons without anyone really noticing. Meanwhile, it's not enough for the U.S. to offer to take back spent fuel—the fuel takes months to cool, and in that time Iran could, again, easily divert it to make weapons.

If Skolski's right on the science, it seems like the only way to deal with Iran is to not let it have any nuclear anything in the first place. Or put its nuclear facilities under extremely close IAEA monitoring and inspections. Bush is trying the first option, by trying to force the UN to place sanctions on Iran. Unfortunately, both Russia and China have opposed sanctions (though Russia sounds like it may cave).

But ignore that. UN sanctions are certainly a good start—if they work—though I don't think it can form the basis of a long-term strategy. The Khomeinists in Iran would almost certainly welcome sanctions as a means of deflecting pressure from the regime, and focusing domestic anger towards the UN. I'm not sure you can deter Iran from wanting nuclear weapons. Even the Khatami-style moderates want a nuclear program, largely as a matter of national prestige. Isolating Iran will only further that desire; so at some point you have to start engaging. If Bush (or Kerry) can get the UN to throw sanctions down, maybe you can go from there. But if not, if sanctions fail, then what? Then maybe the grand bargain becomes the only option, or an option that buys some time. The alternatives—"regime change," an air strike, or an invasion—are not at all viable.