"This paper seeks to answer several critical questions regarding South Korean extended deterrence. How credible is the United States’ extended deterrence umbrella with South Korea? If the credibility of the extended deterrent umbrella is faltering, why is faltering? And finally, how can the United States bolster the strength of its extended deterrence guarantees to South Korea? With all that said, in spite of a dynamic environment and wavering perceptions, the effectiveness and credibility of the United States extended deterrence relationship with South Korea remains strong. Even so, there are several ways in which the United States may be able to bolster its extended deterrent credibility going forward. The analysis in this paper utilizes an assurance assessment model and criteria proposed by Brad Roberts in his book The Case for U.S. Nuclear Weapons in the 21st Century in order to conduct a case study on the recent perceptions and credibility of the United States extended deterrence promises with respect to South Korea. This paper begins with a brief background that lays the foundation of the geopolitical situation in the Indo-Pacific. This section highlights the strategic importance of the region and the importance of the United States-Republic of Korea alliance. The second section will provide an overview of the literature utilized to inform the analysis contained in this paper. The third section covers the theory behind the paper and deterrence. The fourth section will cover the methodology and data utilized to assess the status of the United States-South Korea nuclear umbrella. The fifth section will describe the analysis of the data and the results of that analysis. The final section of the paper will present conclusions and recommendations for the United States to bolster its extended nuclear deterrence and assurance with South Korea."--Page 2.