Civilian air defense revisited

This weekend’s New York Times Magazine has an excellent article on the problems of, and possible solutions to, civilian anti-missile air defense systems.  I remain a believer in the technology, even though the hurdles and costs are far from trivial.  As I’ve previously written, a purely countermeasures focus probably won’t work in the long run because advanced shoulder-fired missile manufacturers would get into an arms race with anti-missile technologies.  The version of the technology that filters down for civilian use is not going to be able to keep up.  The answer might be to develop countermeasure technology (like discussed in the article) that effectively defeats relatively primitive missile designs and encourage or mandate smart “kill switch” functionality for all new missiles manufactured by allies.  If these advanced weapons wind up in the wrong hands, their electronic guidance systems can be automatically and remotely disabled.  Of course, if we get into a war with one of the technologically-sophisticated former allies, the “kill switch” won’t do us any good - but that kind of conflict doesn’t seem to be the geopolitical reality these days.