Today's missile defense decision seems like absolutely the right move to me on both hawkish and dovish grounds. Deploying the sea-based Aegis system will give us a capability that is both more reliable and more appropriate than the questionable coverage that would have been provided by the ground-based interceptors President Bush wanted to place in Poland. The Polish missile defense would have used an untested booster rocket to launch an interceptor that is intended to destroy ICBMs. Given that Iran does not have any ICBMs, it makes more sense to focus on the threat from short- and medium-range missiles that Iran has had more success in developing, which is what the Aegis system does. Moreover, the Aegis SM-3 interceptor actually has a testing track record, albeit a mixed one. (For anyone confused by the various missile defense systems, the Arms Control Association has an enormously helpful chart here.)

And, although Mike is right that the Obama administration doesn’t seem to have gotten anything explicit in exchange from the Russians in return for scrapping Bush’s plan, removing this source of contention from the U.S.-Russian relationship should ease negotiations on a treaty to further reduce nuclear arsenals. Whether it helps us encourage Russia to pressure Iran over its nuclear program is another matter, but it’s hard to see how this would hurt. Poland and the Czech Republic (where we were planning to base a missile-defense radar) are understandably upset by the decision, but given that the missile defense system would have afforded them no meaningful defense against Russia, and given that we can demonstrate our commitment to their defense in other ways, it seems like this decision was a good one.