On the 1,000th day of the Ukraine war, President Vladimir Putin has revised Russia's nuclear doctrine, permitting retaliation even for conventional attacks backed by nuclear powers. This shift follows Ukraine's deployment of US-made ATACMS missiles into Russian territory, heightening tensions. The updated doctrine also includes threats like missile defenses and hypersonic weapons. Kremlin spokesperson Dmitry Peskov called it a 'new phase,' while Russia begins mass-producing mobile nuclear shelters. Meanwhile, Pentagon officials assure there’s no imminent nuclear threat, viewing the move as deterrent.