North Korea’s escalating nuclear threat has reached a critical juncture, with Kim Jong-un openly declaring his intent to use nuclear weapons to attack and annex South Korea. North Korea has also revived its Cold War-era alliance with Russia, further complicating the security dynamics on the Korean Peninsula. In particular, North Korea’s possession of intercontinental ballistic missiles (ICBMs) undermines the credibility of the U.S. nuclear extended deterrence—or “nuclear umbrella”—for South Korea. Consequently, there is an urgent need to explore alternative deterrence mechanisms, one of which is the United Nations Command (UNC). Established in 1950 and currently stationed in South Korea and Japan, the UNC provides a unique multilateral framework that could be leveraged to strengthen nuclear deterrence against North Korea. This chapter examines the historical background of the UNC, analyzes the current security environment on the Korean Peninsula, and evaluates the potential role of the UNC in nuclear deterrence. Based on this analysis, it proposes several measures, including separating the UNC from the United States–South Korea Combined Forces Command and incorporating the UNC into United States–South Korea nuclear consultation mechanisms.