South Korea, US forge 'nuclear-based' alliance against North Korea threats

South Korean President Yoon Suk-yeol said his country's alliance with the United States has been elevated to a "nuclear-based" one capable of deterring North Korea's nuclear threats following their signing of joint nuclear deterrence guidelines.

The US and South Korea last week signed a milestone document laying out nuclear deterrence principles and warned that a doomsday attack on the South "will be met with a swift, overwhelming and decisive response."

The protocols' signing on the margins of the NATO leaders summit comes after Washington and Seoul established in April 2023 the joint Nuclear Consultative Group, which has been working on fleshing out the deterrence document.

"The US will assign a special mission to its nuclear assets for the Korean Peninsula both in wartime and peacetime," Yoon said during a Cabinet meeting, reported Yonhap News.

"We have established a posture to respond swiftly and effectively to any kind of North Korean nuclear threat," he added.

Extended deterrence

The signing of the guidelines was a culmination of the bilateral Nuclear Consultative Group's efforts to ensure the credibility of Washington's "extended deterrence" commitment to South Korea in an integrated way that includes South Korea's conventional support for US nuclear operations in a contingency.

Extended deterrence refers to a pledge from Washington to mobilise the full range of its military capabilities, including nuclear arms, to defend Seoul.