Cold War Military Alliances, Nuclear Proliferation, and Proxy Wars

After World War II, the Soviet Union occupied much of Eastern Europe, forming the Soviet bloc where communist governments were installed.
Western European nations and the United States formed the North Atlantic Treaty Organization (NATO) in 1949 as a mutual defense alliance against the Soviets.
- NATO included the United States and several Western European nations.
In 1955, the Soviet Union formed the Warsaw Pact, a military alliance that included the Soviet Union and Eastern European nations.
Both alliances operated under the agreement that an attack on one member state was an attack on all, requiring a collective response.

The United States pioneered the use of atomic bombs during World War II. The Soviet Union developed their own atomic bombs in 1949, initiating an arms race.
The United States developed the hydrogen bomb, which was more powerful than the atomic bomb.
The Soviet Union responded by developing their own hydrogen bomb.
By the 1960s, both superpowers had amassed enough nuclear weapons to destroy the world multiple times.
Cuban Missile Crisis (1962)
- Following a failed US attempt to oust Fidel Castro, the Soviet Union deployed nuclear missiles to Cuba.
- The US discovered the missile sites and President John F. Kennedy ordered a naval blockade of Cuba.
- The US had previously placed nuclear missiles in Turkey, near the Soviet border.
- The crisis lasted for 13 days, raising fears of nuclear war.
- The missiles were never fired, and eventually, the parties backed down.
Nuclear Non-Proliferation Treaty (1968)
- This treaty called on nuclear powers to prevent non-nuclear countries from developing nuclear weapons.

Proxy wars were indirect conflicts where the United States and the Soviet Union supported opposing sides without directly fighting each other.

After World War II, Korea was divided into North Korea (occupied by the Soviets) and South Korea (occupied by the US and its allies).
In 1950, North Korea invaded South Korea to unify the country under communist leadership.
The United States and the United Nations supported South Korea, while the Soviet Union supported North Korea with weapons and resources.
The conflict ended in a stalemate by 1953, with the border remaining largely the same, but with approximately 3 million deaths.

Angola, a former Portuguese colony, achieved independence after various ethnic groups united against Portuguese rule.
After independence, rival ethnic groups vied for power.
The Soviet Union backed one group, the United States another, and South Africa yet another, leading to the Angolan Civil War.
The conflict became a proxy war between larger powers.

In 1979, the Sandinista National Liberation Front, a socialist group, seized power in Nicaragua.
The United States opposed the socialist government and supported the Contras, who attempted to overthrow the Sandinistas.
The Contras, backed by the US, committed human rights violations during the conflict.
The Sandinistas received support from the Soviet Union.
The conflict ended in a cease-fire.