This paper examines the potential sources of tension in the U.S.-Republic of Korea (ROK) alliance and the future tasks necessary to ensure long term alliance stability. Although the U.S.-ROK alliance remains robust and generally on solid footing, there are at least two key underlying tensions that may lead to wider cracks in the alliance if not properly managed. The first pertains to different perceptions regarding North Korea and how South Korea and the U.S. prioritize diplomatic engagement, inter-Korea relations, and denuclearization. The second relates to questions revolving around South Korean foreign policy autonomy and where the U.S.-ROK alliance fits within this framework. I explore how these tensions play out across different substantive policy areas relevant to the U.S.-ROK alliance moving forward: a) North Korea denuclearization and inter-Korea engagement; b) U.S.-China competition and coordination with the U.S. Indo-Pacific strategy; c) ROK defense modernization; and d) human rights and values-based diplomacy. How these tensions are addressed will be shaped in part by the outcome of South Korean presidential elections in March 2022. All security alliances face periods of tension as alliance relationships ebb and flow in the wake of a changing external security environment and domestic political shifts. As such, alliances must be constantly managed to ensure that they advance the national interests of all parties. Even when alliance partners share common interests and values, a misalignment of strategic objectives exacerbated by alliance misperceptions can undermine the value of an existing partnerships.