When it comes to nuclear weapons, oldies are goodies. Take, for example, the American B61 nuclear device. About the same shape as a 1,000 pound (455 kg) bomb, many NATO fighter bombers were equipped (with the electronics) to use this bomb during the Cold War (and many can still do so). Some 3,200 B61s were built since it entered service in the late 1960s, and about a third of those remain available for use. Some are to be refurbished, but politicians are still debating doing this just to keep B61s good for another two decades. Without the refurb, all these...