On July 27, 1953, North Korea, South Korea, the United States, and the People’s Republic of China agreed to an armistice, ending the brutal three-year fighting between North and South Korea. 

After Korea was freed from Japan’s colonial rule at the end of WWII, the Soviet Union and the United States administered the northern half and the southern half of Korea, respectively. In 1948, a border was set to divide Korea into two sovereign states. A Soviet-backed socialist state was established in the North while a pro-Western capitalist state was created in the South. Peace was short-lived, however, as disputes arose when both governments claimed to be the only authority of Korea and rejected the permanency of the border. 

In June of 1950, tensions escalated to war when roughly 75,000 North Korean soldiers marched across the border and into South Korea. The United Nations responded immediately, sending a coalition force (mostly from the United States) to fight the North Korean invasion. In October, U.S. forces pushed the North Koreans to the north, edging closer to the Yalu River, the border between China and North Korea. In response, Chinese leader Mao Zedong deployed troops to North Korea and warned the U.S. to stay away from the Yalu River.

The first year of fighting ended in a series of battles that were only able to force opposing forces into temporary retreats. As the war bogged down, the last two years settled into a war of attrition: Both sides attempted to win by draining the enemy’s resources and personnel. Air-to-air combat between fighter jets was common, and North Korea was often subjected to U.S. bombing campaigns, becoming one of the most heavily bombed countries in history. Off of the battlefield, the South Korean government secretly killed tens of thousands of suspected communists, while prisoners of war in North Korea died from torture and starvation. Though short, the Korean War was one of the costliest conflicts in the modern era, totaling over five million fatalities, more than half of which were civilian deaths.

The Korean Armistice stopped the destructive fighting, established a Korean Demilitarized Zone that separated North and South Korea, and granted the return of war prisoners. Since then, there has been no major escalation of war concerning both Korean regimes. Though the armistice was not an official peace treaty, it has been a stepping stone for the present-day peace negotiations between the two countries.