Semiconductors have become an integral part of nearly every industry in advanced economies. The production of these semiconductors is largely centered in the western Pacific region and, for the highest-end semiconductors, exists almost entirely in Taiwan. Although this level of industrial base concentration for such a critical economic input raises challenges in and of itself, in this report, we examine the important geopolitical considerations of this concentration. The challenges around Taiwan's relationship with the Peoples Republic of China have not abated and have even accelerated to a degree. Taiwan's market dominance is enmeshed with these geopolitical considerations and requires careful analysis. To explore the geopolitical implications of Taiwan's semiconductor dominance, the RAND National Security Supply Chain Institute conducted a tabletop exercise with representatives from across the executive and legislative branches of the U.S. government and from a variety of industries that rely on semiconductors. Although this exercise did not produce definitive results, it did suggest several important and, to a degree, counterintuitive findings for continued exploration.