Abstract: The fall of the Soviet Union has created complex intra-national security conflicts previously unforeseen to the United Nations (UN), challenging the institution’s efficacy and complicating the United States’ (US) role within the body. As the US continues to oscillate between a leader in international interventions and a removed state that prioritizes its own national security interests, its selectivity has formed a policy of exceptionalism within the United Nations. Throughout the most recent humanitarian conflicts, the US has selectively chosen the UN missions in which it involves itself, otherwise circumventing the Security Council (UNSC) to unilaterally interfere and/or aligning itself with alternative coalitions of the willing to retain the option rather than obligation to intervene. Most importantly, it has directly blocked multilateral negotiations over the Responsibility to Protect (RtoP) (a norm that would codify shared standards under which international intervention is permissible) further complicating the potential for cooperation in crisis. Yet the UN is similarly unequipped to enforce RtoP, as certain institutional barriers such as weak mandates, insufficient communication, and the UNSC unanimity rule impede its ability to enforce and administer peacekeeping operations. Thus, this article argues that both American exceptionalism and institutional UN obstacles hinder the implementation of RtoP, while also reaffirming the norm’s benefits.