Final answer:
The United States and other western nations became involved in the Russian civil war by supporting the anti-Bolshevik White Russians with troops and aid between 1918 and 1920, due to fears of Bolshevism's spread. Their involvement ultimately did not stop the Bolsheviks from taking control after the war, setting the stage for future Cold War conflicts.
Step-by-step explanation:
The United States and other western nations got directly involved in the Russian civil war by sending troops and supporting the White Russians against the Bolsheviks. This intervention occurred between 1918 and 1920, during a period of great upheaval in Russia. The involvement of western nations, including the United States, came as a response to the radical changes brought about by the Russian Revolution and the fear of the spread of Bolshevism, a form of Communism, which was considered a threat to the capitalist order and geopolitical stability. These western nations, led by the Allies, saw the White Russians as a counterrevolutionary force that could overthrow the Bolsheviks and prevent Russia from descending further into Communist control. Historical evidence suggests that around 1.5 million soldiers died during the civil war, and the civilian death toll was even higher, around eight million. Despite direct intervention, the Bolsheviks remained in power after the civil war ended in 1921. The involvement in the Russian civil war laid the groundwork for future conflicts between the United States and the Soviet Union. Throughout the Cold War, the U.S. supported anti-communist forces in various countries, reflecting a continuation of the policies that began during the Russian civil war. The distrust and competition between the two nations evolved, affecting international relations and leading to various proxy wars and standoffs such as the Cuban Missile Crisis.