Command and Conquer: Red Alert is a first Command and Conquer game in the Red Alert Universe. The game takes place in an alternate timeline where Allies and Soviet Union battle for the control of Europe.
This alternate timeline was inadvertently created by Albert Einsten in an attempt to stop the Word War II by eliminating Adolf Hitler. With no Nazi Germany as the balancing power in the Europe, Soviet Union grows as a superpower and tries to take control of the entire Euroasian landmass.