by Ph.D. Daesung SongPresident of AKUS-Korea, Former-President of The Sejong Institute, Korean Air Force Brigadier General (Ret.)
The international system comprises more than 190 sovereign states whose relationships vary widely. Some are adversaries, others maintain limited relations based on narrow interests, and still others cooperate closely in pursuit of shared objectives. Among them are relationships of such strategic consequence that their serious deterioration can directly affect a nation’s security and prosperity.
Looking back on more than seven decades of South Korea’s modern history, and considering the geopolitical environment surrounding the Korean Peninsula today, I regard the ROK-U.S. relationship as one of the most consequential factors shaping the Republic of Korea’s security, development, and prosperity. Since the signing of the Mutual Defense Treaty in 1953, the ROK-U.S. alliance has been a central pillar of South Korea’s national defense. Yet what I mean by “ROK-U.S. solidarity” extends beyond the military alliance itself. It encompasses security and economic cooperation, a shared commitment to liberal democracy and the market economy, and the trust and cooperation that have developed between the peoples of our two countries.
Why, then, should ROK-U.S. solidarity be regarded as an essential foundation for South Korea’s survival and prosperity? I would offer four reasons.
First, ROK-U.S. solidarity provides a critical deterrent against North Korea’s weapons of mass destruction.
North Korea has maintained a three-generation hereditary dictatorship under Kim Il Sung, Kim Jong Il, and Kim Jong Un, while making military power a central instrument of the regime. Despite years of international sanctions, Pyongyang has steadily advanced its nuclear weapons and ballistic missile programs and is now widely regarded as a de facto nuclear-armed state.
According to the SIPRI Yearbook 2026, released in June 2026, North Korea was estimated to have assembled approximately 60 nuclear warheads as of January 2026 and to possess enough fissile material to produce at least 30 more. SIPRI also assessed that North Korea continues to expand its production of fissile material while developing new nuclear delivery systems and further advancing its nuclear forces. Pyongyang has developed a broad missile arsenal ranging from short- and medium-range ballistic missiles to intercontinental ballistic missiles. The U.S. Intelligence Community assesses that North Korea has successfully tested ICBMs capable of reaching the U.S. homeland. North Korea’s nuclear and missile programs therefore no longer pose a threat confined to the Korean Peninsula or Northeast Asia; they have become a direct security concern for the United States itself.
