From Fox News:
Russian President Vladimir Putin signed a revised nuclear doctrine on Tuesday stating that any attack on Russia supported by a country with nuclear power could be grounds for a nuclear response.
Putin signed the new policy on the 1,000th day of the war with Ukraine and the day after President Biden authorized Ukraine to use U.S.-supplied longer-range missiles to strike inside Russia. The doctrine also states that Russia could respond to aggression against its ally Belarus with nuclear weapons, The Associated Press reported.