After a Terrorist Nuclear Attack: Envisaging Catalytic Effects

It is just possible that a terrorist nuclear attack could catalyze an inter-state nuclear war. The likelihood of a terrorist group gaining access to nuclear weapons is lower than some fear, and terrorists might not use a nuclear weapon as soon as they had acquired one. But if a terrorist group was to explode a nuclear device in a country that was itself armed with nuclear weapons, and especially if that country was in a conflict-prone relationship with another nuclear-armed state, the broader consequences of even a single terrorist nuclear detonation could be much more serious than some assume.