New Dem Dispatch on Iran from the DLC calls for "Effective diplomacy backed by the credible threat of force." Obviously, I think it's the case that diplomacy can be rendered more effective through credible threats of force. Unfortunately, an awful lot of people -- especially hawkish Democrats seeking out a sensible middle ground here -- seem slightly confused about the concept of credibility. The credibility of a threat is overwhelmingly an objective property of the threat, and not something that's seriously altered by, say, noting that "all options are on the table." Thus, important aspects of the wisdom of threatening to use force against Iran actually wind up reducing to the wisdom of actually using force against Iran. Or, in the immortal words of Outkast, "don't pull that thang out, unless you plan to bang."

The reason people in the sensible center don't think we should just go bomb Iran next week is that it's quite unclear how much this would really set the nuclear program back, while reasonably clear that it would improve Iran's diplomatic situation and strengthen the hand of the hardliners at home. If I thought (as, say, Reuel Marc Gerecht does) that was wrong; if I thought airstrikes would significantly set back the Iranian program, weaken the Iranian regime, and leave our diplomatic efforts against Iran intact, then it would seem to me that the case for actually bombing after a period of curt diplomacy ("verifiably disarm or we'll bomb you") would be strong. But if you don't believe that -- and I think the sensible center mostly doesn't -- then the threat isn't credible. If a bombing campaign would do more to strengthen the regime and relax its growing diplomatic isolation than it would to set back the nuclear program, then the regime would be relatively eager for us to bomb them. Insofar as they think counterproductive airstrikes are the likely alternative to negotiations, they're less -- not more -- likely to negotiate.

That's the crux of the matter. Credible threats are good. But the threats must actually be credible. If your threat is credible, you can make it clearly and plainly. But it's clear from the overall policy proposal that the DLC (rightly) doesn't regard our threats as very credible. As they say, "our security goals can best be advanced by maintaining a united front with leading powers and world bodies that share our interest in stemming nuclear proliferation and discrediting terrorism." But if the threat's not credible, you're best off not making the threat; you can't magically turn a non-credible threat into a credible one by wishing.