Right from inception, Nigerian foreign policy posture has been Afro-centric. This has made her to be more committed to peaceful coexistence in Africa in general and West Africa sub-region in Particular. Nonetheless, Nigeria has been participating actively in peace operations globally. This study examines Nigeria’s key contributions to the resolution of the Liberian conflict under the ECOWAS Ceasefire Monitoring Group (ECOMOG). While the theory of Manifest Destiny is adopted to explain Nigeria’s leadership role in the resolution, the work derives it data from the secondary source, which consists majorly of textbooks, journals, articles, reports, internet documents, among others. There is an array of information available on the performance of ECOWAS and ECOMOG hence historical research design is used in the study. The study also discusses the challenges of the mission. The findings show that Nigeria’s proactive leadership role in ECOMOG intervention in Liberia was a benchmark for future operations in Africa continent, and that while the holding of elections in 1997 and the subsequent withdrawal of ECOMOG clearly indicate that the operation was a success. The study calls on Nigeria to maintain her Afrocentric foreign policy posture but with more focus on industrialization and economic development of the region.