► Adopted at the recent ROK-US summit, the "Washington Declaration" connects the past, present, and future of the ROK-US alliance, which was formed 70 years ago.

► Based on the foundation of a "value alliance," cooperation has been expanded across five areas, including security, economy, technology, culture, and intelligence.

► The sensitive and concerned response from China, Russia, and North Korea - all of whom are attempting to revise the rules-based international order - to the Washington Declaration indicates that it is working as a new method of deterrence in the face of such countries' strategic calculations.

Adopted at the recent ROK-US summit, the "Washington Declaration" connects the past, present, and future of the ROK-US alliance, which was formed 70 years ago. In this sense, it has significant implications for South Korea in this transitional period.

The Washington Declaration, the first declaration related to peace and stability on the Korean Peninsula, was declared on the same day as the signing of the Korean Armistice Agreement. On July 27, 1953, the day that the armistice agreement was signed at Panmunjom, the sixteen UN states that sent forces to South Korea adopted the "Washington Declaration" in Washington D.C., declaring to "unite and immediately counter any armed attack contrary to UN principles on the Korean Peninsula." After the ROK-US Mutual Defense Treaty went into effect in November 1954, President Eisenhower sent a letter to President Syngman Rhee, emphasizing the importance of the Mutual Defense Treaty and the Washington Declaration. In the letter, President Eisenhower expressed that the US will do its utmost to protect the independence and stability of the Republic of Korea from the threat of communist invasion, reiterating that the two key factors to achieve this were the ROK-US Mutual Defense Treaty and the Washington Declaration.

Now, seventy years later, the ROK-US alliance has evolved into a "global comprehensive strategic alliance." Based on the foundation of a "value alliance," cooperation has been expanded across five areas, including security, economy, technology, culture, and intelligence. Furthermore, through the mutual synergy between these areas of cooperation and the resilience of the alliance, the partnership is developing into an "Alliance in Action Towards the Future." Additionally, the Washington Declaration announced at the recent summit became the first documented commitment to extended deterrence at the presidential level, further upgrading the ROK-US alliance for the next 70 - and even 170 - years.

First, to include the opinions and insights of South Korea as a nuclear deterrence ally in nuclear strategy and planning, South Korea and the US have launched the new Nuclear Consultative Group (NCG). The NCG is distinct from the North Atlantic Treaty Organization's Nuclear Planning Group (NPG) established in 1966 during the Cold War between the US and the Soviet Union. While the NPG includes 30 countries, the NCG is a ROK-US bilateral consultative body focused on the North Korean nuclear threat.

Second, NATO's NPG was launched before the Non-Proliferation Treaty (NPT) went into effect in 1970, but this is the first time that the US has launched a nuclear consultative body with an NPT member country after the establishment of the treaty. Therefore, while the ROK-US NCG is modeled after NATO's NPG, for South Korea, as an NPT member state, the NCG is the most realistic solution for abiding by the NPT while responding to the nuclear threat from North Korea.

Third, joint planning for conventional support from South Korea, cooperation in execution, and enhancement of combined training for US nuclear operations in case of emergencies are crucial elements that qualitatively strengthen America's extended deterrence capability through the joint materialization of "Korean-style extended deterrence."

Finally, the decision to dock strategic nuclear submarines (SSBNs), the stealthiest and most durable form of America's nuclear triad, in South Korea, is a clear response from the ROK-US alliance to the North's "second mission" for its nuclear weapons as revealed through the North Korean Nuclear Forces Policy Act.

The sensitive and concerned response from China, Russia, and North Korea - all of whom are attempting to revise the rules-based international order - to the Washington Declaration indicates that it is working as a new method of deterrence in the face of such countries' strategic calculations.