Korea
The Communist North Korean People's Army (NKPA) crossed the 38th Parallel into South Korea on Sunday, June 25, 1950 with seven infantry divisions and one armored division The US only had twelve active combat divisions, two of which were Marines. The NKPA had Soviet tanks, bombers, and jet fighters; many troops were Soviet trained.
As the UN Security Council held an emergency session and voted to intervene in Korea, the NKPA captured Seoul, the South Korean capital.
The 1st Provisional Marine Brigade landed at Pusan on Aug 7. Along with the 1st Cavalry and 24th Army Division, the 5th Marines fought to drive back the advance of the NKPA around Masan. Using rocket launchers, recoilless rifles, and 90mm fire against the Soviet tanks, the NKPA drew back, harrassed by Marine Corsairs.
After the battle at Masan, General Douglas MacArthur, the commander of UN forces in Korea, began planning an amphibious landing at Inchon. X corps was formed consisting of the 1st Marine Division, 3000 Korean Marines, and 2800 Army troops. Heavy naval and air bombardment preceded the invasion. The 3rd Battalion, 5th Marines went in first and seized the harbor defense guns at Wolmi Island. The beachhead was secured by the end of the first day with minimal opposition. MacArthur pressed on toward Seoul, but the NKPA refused to cooperate, fighting the Marines every step of the way. On September 26 Seoul was recaptured and returned to South Korea.
MacArthur was certain that victory was close at hand and even boasted that his troops might be home by Christmas. He asked the UN Security Council for permission to cross the 38th parallel into North Korea to mop up. The 1st Marine Division was sent to Wonsan and then north to the Yalu River where they encountered pockets of stiff resistance. Terrain was mountainous and a bitter winter was settling in. MacArthur wasn't worried even though he was receiving intelligence of a large buildup of Red Chinese troops near the Yalu.
November 3, the 7th Marines ran into a Red Chinese Division and after four days of battle the Marines came away victorious. MacArthur went ahead with his two prong attack on 24 November: His Eighth Army in western Korea and X Corps with the Marines, in the northeast. Then the Chinese attacked in force.
The Chinese attacked in overwhelming numbers, driving a wedge between the 8th Army and X Corps. The 8th Army was in full retreat. The 5th & 7th Marines were attacked in force at Yudam-ni, west of the Chosin Reservoir, while other Chinese divisions cut the main supply line to the south. For five days the 1st Marine division slugged it out against eight Chinese divisions. 100,000 Chinese against 20,000 Marines. The weather proved to be as fomidable an enemy as the Chinese as the temperature was in the 20's and snowing. Automatic weapons froze and Marines suffered from frostbite.
A withdrawal was ordered. Nearly sixty miles of mountains separated the Marines from the port of Hungnam, their only escape. One Marine Colonel was asked if this was a retreat to which the Colonel replied "Retreat Hell, We're just attacking in a different direction, And we are taking our dead and wounded with us". The Marines had to fight every step of the way as the Chinese continued to attack. Several units suffered 50% casualities. The Marines did get close air support and air dropped supplies from airstrips at Koto-Ri.
Finally on December the battered division made it to Hungnam. It had suffered more than 4000 casualities. The press wrote that the retreat was "America's worst licking since Pearl Harbor". General MacArthur praised the Marines withdrawal "This was undoubtedly one of the most successful strategic retreats in military history". To the Marine Corps the withdrawal from the Choisin Reservoir was a glorious chapter in Marine history. But as great as the retreat was, the UN forces were kicked out of North Korea.
By the end of the year the Chinese had 21 divisions and the North Koreans had 12. Over 500,000 troops with another 1 million Chinese in reserve. The UN had 385,000 troops in Korea, many were South Korean. The Joint Chiefs of Staff wanted to fight a defensive war at the border of North & South Korea. MacArthur disagreed with the Joint Chiefs. He wanted to bomb north of the Yalu, arm Nationalists in Taiwan, and push ahead to victory. His Defiance ultimately got him relieved by President Truman in April 1951.
The armistice was signed on July 27 1953, The Marines suffered 30,544 casualties including 4,262 killed in just over three years of fighting. Congress passed a law durng the final months of the Korean war which kept the strength of the Marine Corps at three divisions and three air wings. Most importantly the commandant was given a seat on the Joint Chiefs of Staff although he didn't become a full member until 1976.
