President Vladimir Putin has announced significant changes to Russia's nuclear doctrine, a move that comes just two days after President Joe Biden authorized Ukraine to use US-manufactured weapons for strikes within Russian territory, CNN has learned.
The updated doctrine, released on Tuesday, establishes that Moscow will treat any aggression from a non-nuclear state that involves a nuclear-armed nation as a combined assault against Russia.
Speaking to reporters on Tuesday, Kremlin spokesperson Dmitry Peskov explained that "the Russian Federation reserves the right to use nuclear weapons in the event of aggression using conventional weapons against it and/or the Republic of Belarus."

The revision appears to expand Russia's definition of what constitutes aggression against the nation, with nuclear deterrence remaining a fundamental component of Russian military strategy, according to CNN.
"An important element of this document is that nuclear deterrence is aimed at ensuring that a potential adversary understands the inevitability of retaliation in the event of aggression against the Russian Federation or its allies," Peskov told reporters, as reported by CNN.
The Kremlin's announcement of nuclear policy modifications arrives as Russia responds to the Biden administration's decision permitting Ukraine to employ advanced long-range American weaponry within Russian borders. Russian officials have previously indicated to CNN that such a move would represent a dangerous escalation of the conflict in Ukraine.
According to Bloomberg, Ukraine has conducted its first strike within Russian territory using American-provided missiles, coinciding with Moscow's announcement of broader nuclear weapon usage criteria. According to RBC Ukraine, citing military sources, Ukrainian forces targeted a facility in Russia's Bryansk region using ATACMS missiles, marking the first such deployment since Washington authorized their limited use against Russian targets.
Ukrainian military leadership confirmed striking an ammunition depot in Karachev, located approximately 71 miles from the Ukrainian border, resulting in the detonation of stored munitions. Military officials declined to specify which weapons were employed in the operation, citing security protocols.