Russian President Vladimir Putin announced an update to Russia’s nuclear doctrine on Tuesday, expanding the conditions under which the country might use nuclear weapons. This move came shortly after Ukraine used American-made ATACMS missiles to strike a Russian target.

The revised policy outlines new scenarios for nuclear use, including conventional attacks on Russia or its ally Belarus that threaten their sovereignty or territorial integrity. It also considers attacks by non-nuclear states supported by nuclear powers, as well as mass aerospace assaults—such as missile and drone strikes—that cross Russian borders. Additionally, Russia now views any aggression from a military coalition like NATO as an attack by the entire alliance.

The Kremlin framed these changes as a means to clarify its deterrence strategy and reinforce the inevitability of retaliation against aggressors.

Amid recent developments, the United States temporarily closed its embassy in Kyiv on Wednesday, citing threats of a “significant air attack” from Russia. As a precautionary measure, embassy staff were instructed to shelter in place, with similar closures announced by Italian and Greek embassies. The U.S. State Department expects normal embassy operations to resume Thursday.