This graduate major paper critically analyzes the diplomatic aftermath of the assassination of Haitian President Jovenel Moïse, focusing on both domestic instability and international responses. The study explores how the power vacuum, gang violence, and legal ambiguities deepened Haiti's ongoing crisis, while revealing the challenges faced by diplomatic actors including the United Nations, the United States, Colombia, and regional organizations such as CARICOM. Using a case study approach, this paper assesses the implications of foreign interventions, past peacekeeping missions (like MINUSTAH), and ongoing missions (such as BINUH), while reflecting on international law, sovereignty, and diplomatic restraint. The work also addresses issues of governance, police reform, and human rights in the context of Haiti’s fragile statehood. The paper offers actionable policy recommendations to promote sustainable peace, strengthen state institutions, and improve Haiti's international diplomatic engagement. It contributes to the discourse on crisis diplomacy, post-conflict governance, and Caribbean geopolitics.