Vladimir Putin’s announcement that Russia may resume nuclear testing marks one of the most dangerous escalations in global security since the Cold War. He has instructed senior military and intelligence officials to prepare proposals for possible tests at the Novaya Zemlya site in the Arctic - where the Soviet Union in the past had detonated more than 200 nuclear devices, but none since 1990. The move follows Donald Trump’s declaration that the USA would restart its own nuclear tests, for the first time since 1992. Both leaders’ actions revive fears of an uncontrolled arms race, just as the last major nuclear treaty between Washington and Moscow nears expiry. Analysts warn that renewed testing could shatter global non-proliferation norms and invite imitation from other states.