It was bad enough that Washington and Moscow decided to end the Intermediate-range Nuclear Forces Treaty (INF) when it expires in August. Now, Russian President Vladmir Putin has complained that the United States is showing little interest in discussing the renewal of another vital measure of arms control, the New Strategic Arms Reduction Treaty (Start), signed in 2010 by then President Barack Obama and his counterpart at the time, Mr Dmitry Medvedev. The New Start, which ends in 2021, caps deployed US and Russian strategic nuclear arsenals at 1,550 warheads and 700 missiles and bombers each and allows the two sides to extend the pact for up to five years until 2026 without requiring US Senate approval.

While his claim that shelving the treaty could actually help Russia cement its purported lead in new-generation weapons may be a bit of a boast, Mr Putin has to be taken seriously when he says that allowing it to lapse would spur a nuclear arms race. The near certainty that this could extend to weaponising space makes it particularly alarming - it is bad enough that there are already too many nuclear bombs ready to be launched from the air, land and sea. All this adds another hard edge to a world increasingly nervous about tensions building up in the Indo-Pacific in the wake of a full-blown trade war between the US and China, and where military manoeuvres can easily go dangerously wrong.