The conventional wisdom across the political spectrum says an Iranian nuclear weapon is "unacceptable." But what if it isn't? What if it comes down to a decision to attack Iran, and that option, it turns out, is "unacceptable" too? Then what?

That's the question former New York Times executive editor Bill Keller asked himself this morning in a column, and his conclusion might surprise: We can live with a bomb. Keller reviews some of the few instances of "serious, thoughtful people who are willing to contemplate a nuclear Iran," and ends up siding with them:

After immersing myself in the expert thinking on both sides, I think that, forced to choose, I would swallow hard and take the risks of a nuclear Iran over the gamble of a pre-emptive war. My view may be colored by a bit of post-Iraq syndrome.

The "post-Iraq" distinction seems to be key, and a frank admission from Keller. The experience—years of war, thousands of deaths, billions of dollars, and for what?—chastens many liberal hawks, though not all. Neoconservative hawks, those who led the charge to war with Iraq by successfully enlisting their liberal counterparts, seem to have no such compunctions.

That's why Keller's sober assessment is worth reading in full. He runs down many of the "unacceptable" arguments, but also outlines the complications and "grave costs" of an attack, most notably "a redoubled determination by Iran’s leaders to do the one thing that would prevent a future attack: rebuild the nuclear assembly line, only this time faster and deeper underground."

Keller concludes on an optimistic note, that the best way forward would be a deal that strictly enforces boundaries on Iran's civilian nuclear program. It's for now, at least, wishful thinking; the current, precarious stasis has Iran not building a bomb, and the West not bombing it.

In his essay, Keller adds usefully that he's "tended to duck" questions about, as he says the Israelis put it, "“Bomb? Or The Bomb?” He's right that, to maintain pressure on Iran, American political leaders mayn't freely ask these questions in public. (Neocons advising Romney have said Obama administration officials shouldn't even be frankly discussing potential consequences of a strike.) But for the Kellers of the world—and the rest of us—this discussion should be a welcome one.