The game's story line starts off in 1972, with the United States Armed Forces caught completely off guard by the sudden massive Soviet invasion of the United States, with Soviet aircraft, naval vessels, amphibious forces, and paratroopers coming in on both the East Coast and West Coast and with the majority of Soviet ground forces coming in through Mexico, starting World War III. Romanov acquiesces to the Allies' demands at first, though he builds up the Soviet military for 'defense purposes' – a cover for an intended invasion of the United States. Fearing that a regime change would cause mass unrest in the Soviet Union, the victorious Allies installed Alexander Romanov, a distant relative of Tsar Nicholas II, as the puppet Soviet Premier.

With Hitler gone, the Soviet Union led by Joseph Stalin attempted to conquer Europe but was defeated by the Allied nations and their military destroyed. Red Alert 2 is set in the same alternative history universe as Red Alert in which Adolf Hitler was removed from history. Like previous Command & Conquer real-time strategy games, Command & Conquer: Red Alert 2 contains two separate campaigns with distinct story lines, one for each playable faction.

Red alert 2 demolition truck