Everything You Need to Know: The History of U.S. Nuclear Weapons in South Korea

September 9, 2017 Topic: Security Region: Asia Blog Brand: The Buzz Tags: WarTechnologyMilitaryWeaponsCold WarNuclearMissiles

Everything You Need to Know: The History of U.S. Nuclear Weapons in South Korea

And could they go back.


American tactical nuclear weapons were stationed on the Korean Peninsula for much of the Cold War, on call and ready to repel a North Korean attack. Nuclear bombs, artillery shells and missile warheads were withdrawn from Korea in 1991. Now, as reports surface—and are later denied—of South Korean requests to return tactical nuclear weapons to U.S. bases in Korea, it’s a good time to reflect on the history of the weapons and why they were sent to the country in the first place.

The U.S. history of nuclear weapons and Korea dates back to the Korean War, when President Harry S. Truman debated using nuclear weapons to stanch the China’s Thanksgiving counteroffensive. The following spring, nine nuclear bombs were transferred to Okinawa, along with nuclear-capable B-29 bombers, in case the decision was made to use them. Truman went so far as to predelegate authority to use the bombs to Gen. Matthew Ridgway, commander of U.S. forces in Korea, but Ridgway declined to use them.


Nuclear weapons were first based on the Korean peninsula in 1958, as a result of the U.S. Army’s reorganization of combat divisions into the so-called “Pentomic” structure thought to be ideal for battlefield nuclear warfare. U.S. Army forces in Korea received M442 nuclear shells for 203mm (8-inch) howitzers. Armed with a twelve-kiloton W33 nuclear warhead, the M442 had a range of eleven miles. Army forces in Korea also received the Honest John artillery rocket, widely considered the first American tactical nuclear weapon, with had a range of 5.3 to 15.7 miles. Honest John was equipped with a W7 warhead with a yield of ten kilotons or a W31 warhead with a sixty-kiloton yield.

Under army control, the M442 and the Honest John would be used against advancing waves of North Korean troops, wiping out entire brigade-sized formations of the Korean People’s Army with the heat and blast of a nuclear explosion and contaminating the area with deadly radioactive fallout. Another weapon deployed in 1958, the atomic demolition mine could be placed along likely North Korean advance routes. Highly mobile at just sixty pounds, the mine could be deployed just before an attack and had a yield of twenty kilotons.

In 1958, the U.S. Air Force deployed fifteen Matador cruise missiles in South Korea. Matador missiles flew at subsonic speeds, had a 620 mile range and carried a forty-kiloton nuclear warhead. The missiles, under the control of the 310th Tactical Missile Squadron at Osan Air Base, were only briefly in service before being withdrawn in 1961. Matador missiles would have almost certainly have been launched at Pyongyang and other strategic North Korean locations.

The U.S. Army deployed Nike Hercules surface-to-air missiles to South Korea in 1961. Nike Hercules had an effective range of seventy-five miles and included the W7 warhead with a yield of two or twenty kilotons and later the W31 with a yield of two, twenty or forty kilotons. Rumor has it one mission of Nike Hercules batteries in South Korea was to use them as surface-to-surface missiles, laying down a carpet of radioactivity along the DMZ. Although the rumor has yet to be corroborated, Nike Hercules did have a surface-to-surface capability and was the basis for South Korea’s first generation surface-to-surface missile, NHK-1, or Hyunmoo-1.

In 1961 the air force replaced the Matador cruise missile with the Mace, and by 1962, the U.S. Army in Korea added the Sergeant surface to surface missile, a missile with a 200 kiloton nuclear warhead and a range of seventy-five miles. The M28/29 Davy Crockett tactical nuclear recoilless rifle, with a ten to twenty ton nuclear yield, was in service in Korea from 1962 to 1968. In 1964, the Army deployed the M454 155mm nuclear artillery shell with the W48 warhead. The W48 warhead was sub-kiloton in yield, providing an explosive equivalent to just 70 to 100 tons of TNT.

The U.S. Air Force maintained an arsenal of nuclear gravity bombs in Korea. B43 and B57 bombs were likely stored on the peninsula, and B61 bombs were stationed in South Korea when all nuclear weapons were ordered removed in 1991. Air Force F-4D Phantom II fighters were the delivery vehicles and nuclear bombs were stored at Osan Air Base, Kunsan Air Base, and Kwangju Air Bases.

U.S. tactical nuclear weapons deployed to South Korea were kept a high state of readiness, not only as a hedge against a no-notice invasion by North Korea but also as part of the Single Integrated Operating Plan, or SIOP, that would govern an all-out nuclear war. As part of the SIOP, the 8th Tactical Fighter Wing at Kunsan Air Force Base kept four Phantom fighters loaded with nuclear weapons ready at all times.

At the height of the Cold War deployment, U.S. nuclear weapons in South Korea numbered approximately 950 weapons of all types. By the 1970s the Army and Air Force had phased out all nuclear rockets, surface to surface missiles, and cruise missiles from South Korea, leaving artillery shells and gravity bombs the only tactical nuclear weapons remaining in-country. The United States pulled all tactical nuclear weapons out of South Korea in 1991.

If United States and South Korea agreed to return tactical nuclear weapons to the Korea, what weapons are available? With the dismantling of the last tactical nuclear artillery shell in 2003, the only remaining tactical nuclear weapons in the U.S. arsenal are an estimated 500 B-61 gravity bombs. U.S. Air Force F-16 Fighting Falcon fighter bombers based at Osan or Kunsan Air Bases are the logical deployment systems for the B-61.

The deployment of tactical nuclear weapons to South Korea lasted decades before being ended in 1991. North Korea’s development of nuclear weapons and nuclear delivery systems arguably makes such weapons vulnerable to attack. While B-61 bombs in South Korea would make them more responsive to U.S. forces in an emergency, they would be less secure, vulnerable to North Korean missiles. They might also force North Korea into developing a doctrine for tactical nuclear warfare, making them more likely to be used in a general war scenario. The era of tactical nuclear weapons based in South Korea is likely over.

Kyle Mizokami is a defense and national security writer based in San Francisco who has appeared in the Diplomat, Foreign Policy, War is Boring and the Daily Beast. In 2009 he cofounded the defense and security blog Japan Security Watch. You can follow him on Twitter: @KyleMizokami.

ImageA frontal view of four B-61 nuclear free-fall bombs on a bomb cart.​