How should the West respond to Putin’s nuclear threats?

Can this really be happening? Sadly, the answer is yes. President Putin has just reiterated his threat to use nuclear weapons and announced that Russian-controlled Ukrainian territory will become part of the Russian Federation.

Is nuclear weapon use likely or certain? No, not by any means, and we should speak with a sense of proportion and care. Putin wants us to be frightened. But we also need to stop burying our heads in the sand, as we have done with Russia for too long. To minimise the chances of nuclear use – tactical or strategic – we must assume that the threat is real and that at some point, probably as Russian troops face major collapse in south-east Ukraine over the next six to nine months, Putin will either use or come close to using tactical nuclear weapons. At every point he has chosen to escalate and increase risk. There is no sign that he will do anything different.