Moscow’s doctrine allows for a nuclear attack after “aggression against the Russian Federation with conventional weapons when the very existence of the state is threatened”.Since Russia invaded Ukraine almost a year ago on February 24, Medvedev has repeatedly raised the threat of nuclear chaos and used insults to describe the West.Putin casts Russia’s “special military operation” in Ukraine as an existential battle with an aggressive and arrogant West and has said that Moscow will use all available means to protect itself.Russia’s February 24 invasion of Ukraine has triggered one of the deadliest European conflicts since World War II and the biggest confrontation between Moscow and the West since the 1962 Cuban Missile Crisis.The United States and its allies have condemned the invasion of Ukraine as an imperial land grab, while Ukraine has vowed to fight until the last Russian soldier leaves its territory."