The Cold War was a period of heightened military and political tensions between the United States and its allies on one side and the Soviet Union and its allies on the other. Both superpowers engaged in a variety of contests against each other, including military brinkmanship and proxy wars in smaller countries to spread their ideologies. Ultimately, the economic engine of capitalism won out and the Soviet Union collapsed.
The Cold War began in the wake of World War II. As the Allies attacked Germany from both sides, the Soviet Union took considerable amounts of territory, including much of Germany itself. After the war, the Soviets installed governments in these captured countries, absorbing them into itself or forging strong diplomatic ties in the Warsaw Pact. The Allies liberated the countries on the Western front, and several of these countries joined the North Atlantic Treaty Organization to stand against the Soviets.
Many of the armed conflicts from the 1950s to the 1980s occurred against the backdrop of the struggle between the superpowers. In many cases, the Soviet Union incited local insurgents to rise up and overthrow their governments, replacing capitalist systems with Communist ideology. The United States opposed these efforts, often helping the local governments resist with extensive military aid or, in some cases, direct military intervention. Notably, the wars in Korea and Vietnam were directly tied to the Cold War.