The Kremlin has had little success invoking its nuclear arsenal to deter Ukraine and the West from using new tactics to stop Russia’s invasion. That may be changing.

A close ally of President Vladimir Putin warned Western governments on Thursday that a nuclear war would ensue if they gave the green light for Ukraine to use long-range Western weapons to strike targets deep inside Russia.

On Wednesday, the Kremlin condemned comments by outgoing NATO chief Jens Stoltenberg as “dangerous”, Reuters reports. Stoltenberg had suggested that allowing Ukraine to use Western long-range missiles to strike Russian territory would not trigger an escalation from Moscow.