The cold war lasted for more than fifty years and polarized the world. Rooted in political and ideological disagreements dating back to the Russian Revolution of 1917, the war emerged from disputes that intensified in the wake of World War II. In The Cold War: A History in Documents, Second Edition, Allan M. Winkler excerpts speeches by Soviet premier Joseph Stalin and British prime minister Winston Churchill in order to demonstrate the growing abyss betweenthe two political systems. President Harry S. Truman's announcement of the existence of a Soviet atomic bomb and his speech to Congress launching the Truman Doctrine testify to the gravity of the situation. The complex politics of the Vietnam War appear in voices of those as divergent as Vietnamesenationalist Ho Chi Minh, President Lyndon B. Johnson, antiwar protestors, and a participant in the My Lai massacre.