The Korean missile war is heating up.

Ever since the United States and North Korea agreed to an armistice in 1953, the Korean Peninsula has enjoyed at best an uneasy peace. Now, the frozen conflict could enter a new phase as Pyongyang's tests increasingly powerful ballistic missiles—and, in response, Washington sends more missile-defense troops to the region.

On June 7, 2016, the Pentagon announced that it would send a US Army unit with Terminal High Altitude Air Defense—aka THAAD—missiles to South Korea. Washington and Seoul had been discussing the deployment for four months.

The two countries still have to decide where the troops will be based and other specifics about the mission. The Army already maintains a number of Patriot surface-to-air missile launchers at air bases in South Korea.

"Nuclear test[s] and multiple ballistic missile tests … highlight the grave threat that North Korea poses to the security and stability of … the entire Asia-Pacific region," the South Korean government declared in an official statement. "When the THAAD system is deployed to the Korean Peninsula, it will be focused solely on North Korean nuclear and missile threats."

Prototype North Korean Musudan missile fires up during an apparently successful test in June 2016. Photo: North Korean state media

Since January, the reclusive Communist regime has fired at least six prototype Musudan land-based ballistic missiles, two KN-11 submarine-launched types and an Unha-3 space launch rocket. All of these could, in theory, carry a nuclear warhead. Four separate United Nations Security Council Resolutions have condemned Pyongyang's missile tests and called on the country to halt any future launches.

On top of this, on January 6, 2016, North Korean authorities claimed to have successfully set off a powerful thermonuclear weapon—a hydrogen bomb—in their fourth atomic test since 2006. Separately on June 8, Washington hit North Korean leader Kim Jong-Un with additional new sanctions over his human rights abuses.

"They continue to prioritize missile and nuclear weapons programs over the well-being of their own people," US Navy captain Jeff Davis told reporters at the Pentagon in February, after announcing the Pentagon had sent its latest report on North Korea to Congress. "We … will take all necessary steps to defend ourselves and our allies and respond to North Korean provocations."