The Ukraine War is an event in which the core values and norms of the US-led liberal rule-based order in the post-Cold War era, are directly challenged. While the leadership of the United States is weakening, great powers such as Russia and China are trying to present an alternative order to realize their own interests and values. As the competition for world order is intensifying, the symbolic event that opens the new chapter is the Ukraine war. The war has great implications not only for Europe's security landscape, but also for the global security situation, as well as East Asia and Korea. there is. If Russia's illegal war achieves territorial acquisition or expansion of its sphere of influence in some or all of Ukraine, this will have great implications for other countries. Also, if a military advantage is gained by using low-yield nuclear weapons in the course of war, this will also have great implications for other countries. All of these changes in the security environment surrounding South Korea have great meanings, so the analysis of the war in Ukraine is very meaningful. This article first examines the historical background and controversy surrounding the cause of the Ukraine war, and examines the implications of the war in international politics and security order. Following the analysis of changes in the security order in Europe after the war in Ukraine, the balance of power in East Asia and the Korean Peninsula issue, especially the North Korean nuclear issue, will be analyzed with their implications.