Russian President Vladimir Putin on Tuesday approved an updated nuclear doctrine, saying that Russia could consider using nuclear weapons if it was subject to a conventional missile assault on it supported by a nuclear power, Reuters reported.

The decision to change Russia’s official nuclear doctrine is the Kremlin’s answer to a reported decision by the administration of U.S. President Joe Biden to allow Ukraine to fire American long-range missiles deep into Russia.

The updated doctrine, which outlines the threats which would make Russia’s leadership consider a nuclear strike, said an attack with conventional missiles, drones or other aircraft could be considered to meet these criteria.

It also said any aggression against Russia by a state which was a member of a coalition would be considered by Moscow to be aggression against it by the whole coalition, read the report.

Just weeks before the November U.S. presidential elections, [USN:L8N3L71Q3 TEXT:“Putin ordered”] changes to the nuclear doctrine to say that any conventional attack on Russia aided by a nuclear power could be considered to be a joint attack on Russia.

The 2-1/2-year-old Ukraine war has triggered the gravest confrontation between Russia and the West since the 1962 Cuban Missile Crisis – considered to be the closest the two Cold War superpowers came to intentional nuclear war.