He declared that a conventional attack by any nation supported by a nuclear power will be considered a joint attack on Russia.

Vladimir Putin has approved changes to Russia’s nuclear doctrine, setting out new conditions under which the country would consider using its arsenal. The doctrine now says an attack from a non-nuclear state, if backed by a nuclear power, will be treated as a joint assault on Russia.

Russian President Vladimir Putin signed a revised nuclear doctrine stating that any attack on Russia supported by a country with nuclear power could potentially trigger a nuclear response.