The Korean War in pictures

• China intervenes
• The war had different names depending on the region
• The pre-war partitioning of Korea
• Joseph Stalin was instrumental in the start of the war
• The war begins in 1950
• South Korean forces were decimated in a matter of days
• The U.S. gets directly involved
• The United Nations condemns the invasion
• American forces were initially unsuccessful
• The Battle of Incheon
• MacArthur sets his sights on North Korea
• China intervenes
• Border fighting and the fall of MacArthur
• A two-year stalemate
• A new president, and the death of Stalin
• Armistice reached in 1953
• The DMZ is established
• The aftermath for North and South Korea
• The damage to the entire region was extensive
• Lack of media attention
• The war is still not technically over

China intervenes

From 1950 to 1953, North and South Korea were locked in a bitter and bloody war, and the ramifications of this conflict reverberate to this day. Learn more about the Korean War and how it unfolded, as well as the impact on modern-day North and South Korea.

The war had different names depending on the region

What is the name for the conflict that unfolded in Korea from 1950 to 1953? The answer varies depending on who’s asking. In South Korea, it’s usually referred to as the “625 Upheaval” or the “625 War,” referencing the date it started: June 25. In North Korea, it’s officially known as the “Fatherland Liberation War.” Mainland China most commonly calls it “Resist America and Assist Korea.” While “Korean War” is how most people in the United States, Taiwan, Hong Kong and Macau know it, technically the U.S. never formally declared war on anyone, and the operation—or “police action”, as President Harry S. Truman described it—was officially carried out by the United Nations.

The pre-war partitioning of Korea

When World War II ended in 1945, Korea was liberated from Japanese control. The United States and the Soviet Union agreed to temporarily divide Korea at the 38th parallel of latitude north of the equator. This partitioning resulted in the formation of two new countries: North Korea, occupied by the Soviets, and South Korea, occupied by the United States. While the Soviet Union assumed control of North Korea and established a communist government, the independent Republic of Korea (ROK)—also known as South Korea—was formed in August 1948.

Joseph Stalin was instrumental in the start of the war

By 1949, rumblings of a war were getting stronger, and international events appeared to set the stage: Mao Zedong and the People’s Liberation Army secured victory in China, American forces had withdrawn from Korea, and the Soviet Union detonated their first nuclear bomb. Soviet leader Joseph Stalin believed that the U.S. would not be very willing to fight in Korea, given its lack of direct intervention to stop the communist victory in China. Stalin’s position was only reinforced after reading dispatches from the U.S. to its embassy in Moscow, the codes having been cracked by the Soviets. Based on these developments, Stalin executed a more aggressive strategy in Asia, giving North Korea permission to attack the South, under the condition that China would agree to send reinforcements if needed.

The war begins in 1950

On June 25, 1950, around 75,000 soldiers from the North Korean People’s Army (KPA) stormed across the 38th parallel, under the direction of the communist leader of North Korea, Kim Il-sung. The invasion was considered a surprise—in 2010, declassified CIA documents revealed that both the United States and the South Korean government were caught unprepared for the conflict, due to failures in intelligence as well as incorrect assumptions. Even though the Cold War technically began following World War II, this invasion marked the first official military action of the conflict between the U.S. and the Soviet Union and their respective allies.

South Korean forces were decimated in a matter of days

The first few days of the war went very poorly for the South Koreans, who lacked the skills, weapons or defences against the well-trained KPA, which also boasted tanks and heavy artillery. South Korean President Syngman Rhee evacuated the capital city of Seoul on June 27, and the city itself fell a day later. By the end of the month, the ROK Army was down to fewer than 22,000 troops, after starting the war on June 25 with 95,000.

The U.S. gets directly involved

Just days after the invasion, U.S. President Truman and his advisors decided to back up their policy of containment when it came to the threat of communism spreading in the world. The Americans were convinced that the Soviet Union was backing the KPA, and reached out to the United Nations to rally support for South Korea, arguing that the North Korean invasion was comparable to Adolf Hitler’s aggressions in the 1930s.

The United Nations condemns the invasion

As the United States prepared to enter the war, the United Nations Security Council passed a pair of resolutions, one unanimously condemning the invasion, and another recommending that UN member states provide direct military assistance to the Republic of Korea. Interestingly, the Soviet Union was boycotting the Security Council at the time, over a dispute regarding the admission of China to the UN. The Soviets could have vetoed the resolutions as a permanent member, but due to the boycott, the council passed the resolutions successfully.

American forces were initially unsuccessful

When American forces stationed in Japan first joined the foray directly in July and August of 1950, they didn’t exactly turn the tide right away. U.S. soldiers did not have adequate weaponry nor leadership, and also had to deal with refugees fleeing south. Add in the fact that the summer of 1950 was one of the hottest and driest on record, and these conditions were not conducive to gaining ground against the KPA—at least not until September.

The Battle of Incheon

On September 15, 1950, the Battle of Incheon took place in the western port city near Seoul, and completely swung the advantage to the South Koreans, led by the United Nations Command and U.S. Army General Douglas MacArthur. In a matter of days, the bold amphibious assault involving 75,000 troops and more than 250 naval vessels secured Incheon, leading to the recapture of Seoul two weeks later and a rapid collapse of the KPA, which saw its supply lines partially severed and hundreds of thousands of troops taken prisoner.

MacArthur sets his sights on North Korea

Emboldened by the success in Incheon and with the South Korean government restored in Seoul, MacArthur now turned his attention to north of the 38th parallel. After receiving the go-ahead from the Joint Chiefs of Staff, the UN Command and the ROK Army pushed the KPA back into North Korea in October, capturing Pyongyang on October 19.

China intervenes

The Korean War very likely would have ended in the fall of 1950, were it not for the intervention of China. Even as UN and ROK forces were entering North Korea, Chinese soldiers and Soviet Air Force troops were mobilizing, and in November they drove MacArthur and his troops back across the 38th parallel.

Border fighting and the fall of MacArthur

The Chinese government now desired a total victory over the UN with a united Korea under their rule. On January 4, 1951, it appeared to get closer to that goal, capturing Seoul for a second time. The UN responded in kind, however, and by March had regained control of Seoul once again. Even still, the Americans were not pleased with the mistakes made by General MacArthur, in particular his belief that China would not enter the war, and later his direct threats towards China itself, as well as his threats of using nuclear weapons. On April 11, President Truman removed MacArthur as Supreme Commander for insubordination.

A two-year stalemate

By the summer of 1951, the casualties were piling up for both sides. The Chinese and North Korean had suffered half a million since the previous November, and the UN Command had lost more than 100,000 since the Chinese intervention. The leaders of both sides began to consider a settlement to end hostilities. For more than two years, they kept negotiating, while on the front lines, a “stalemate” was observed, where both sides essentially gave up on the notion of uniting Korea by force, and movement was never again as fluid as in the first year of the war.

A new president, and the death of Stalin

Two key moments in the Korean War happened thousands of miles away from the battles. The first came in late 1952, when the United States elected a new president, Dwight D. Eisenhower, who travelled to Korea to determine what could end the war. A few months later, Soviet leader Joseph Stalin died, and the new regime in Moscow was too preoccupied with their internal power struggle to continue supporting China’s efforts in Korea. This accelerated the talks for an armistice.

Armistice reached in 1953

After more than two years of negotiations—and over three years of brutal battles—the Korean Armistice Agreement was signed on July 27, 1953. This ended the war for all intents and purposes, however there was never a formal peace treaty, and South Korean president Syngman Rhee also refused to sign the agreement.

The DMZ is established

As part of the armistice, the Korean Demilitarized Zone was established roughly along the 38th parallel in order to serve as a buffer between North and South Korea. At 250 km (155 miles) long and 4 km (2.5 miles) wide, the DMZ is still patrolled by the KPA and ROK forces today. Many cases of incidents have been reported over the years, with military and civilian casualties on both sides.

The aftermath for North and South Korea

The postwar recovery period looked very different in the two Koreas. When the war began, South Korea was the lesser-developed of the two in terms of industry, but it modernized quickly following the Vietnam War, and had one of the fastest-growing economies in the world from the early 1960s to the late 1990s. Meanwhile, North Korea’s industrial society was almost completely destroyed, and even though it received assistance from both the Soviet Union and China, it has remained underdeveloped and run as a totalitarian dictatorship.

The damage to the entire region was extensive

Despite lasting just over three years, the Korean War was one of the bloodiest wars in the Cold War era. The estimates for total casualties range from three million to nearly five million people, and more than half of the approximate figure were civilians, a higher rate than both World War II and the Vietnam War. North Korea suffered the worst of the devastation, losing as much as 15% of their entire population. Virtually all of the major cities on the Korean Peninsula were destroyed.

Lack of media attention

Even though the Korean War had a profound impact on the region that is still being felt today, the rest of the world didn’t give it very much attention. It’s often referred to as “The Forgotten War” because of the lack of public attention it received both during and after the war, especially when compared to the preceding World War II and the succeeding Vietnam War. It wasn’t until the 1970s—largely thanks to the smash hit American TV series M*A*S*H—that the English-speaking world was made fully aware of the scope of the destruction.

The war is still not technically over

While the armistice was declared in 1953, the Korean War has still not come to a formal end. Acts of aggression from North Korea and a lack of serious talks between the two sides over the decades have resulted in an inability to come to a final agreement. As recently as 2021, South Korean President Moon Jae-in has advocated for a formal declaration, and while an agreement has been made in principle between the two Koreas, the United States and China, North Korea’s demands have stalled talks indefinitely.