How Worried Are You?

One of the many unintended consequences of the Russian invasion of Ukraine is the renewed discussion among politicians, as well as in the popular media, of nuclear war. How worried should we be about Russian or Korean or Chinese or prospectively Iranian nukes? Have we suddenly moved from a world of nonproliferation to a world of proliferation? Dr. Tytti Erästö is an expert on nuclear weapons at the Stockholm International Peace Research Institute (SIPRI). For her, a key assumption has long been that rational leaders would never use nuclear weapons. But now she is asking, what about irrational ones?