The Korean War began with North Korean leader Kim Il-sung launching an attack on Seoul, South Korea’s capital on June 25, 1950. This attack, was made with the tacit approval of Soviet dictator Joseph Stalin and three days later, Seoul succumbed to Kim’s forces.
On June 27, then-US president Harry Truman ordered the US Seventh Fleet to the Taiwan Strait to protect Taiwan from invasion by communist forces. Subsquently, a UN force, led by General Douglas MacArthur, was formed on July 7, following a decision by the UN Security Council. Those forces landed at Incheon shortly after and pushed the forces of North Korea back. At this point, however, Kim called on Mao Zedong (毛澤東) to dispatch his troops to the Korean Peninsula.