This study delves into the diplomatic and peace-building endeavors of the Economic Community of West African States (ECOWAS) through the lens of its military intervention arm, the ECOWAS Ceasefire Monitoring Group (ECOMOG), focusing on its operations in Liberia and Sierra Leone from 1989 to 2004. Despite the intensification of intrastate conflicts in West Africa over the past twenty-five years, traditional conflict resolution mechanisms employed by regional leaders have proven insufficient in curbing violence. Thus, ECOWAS has increasingly turned to military intervention as a means of creating conditions conducive to diplomatic negotiations and traditional conflict resolution methods. ECOMOG, a nonstanding force comprised of troops from West African militaries, has been deployed in Liberia, Sierra Leone, Guinea Bissau, and Côte d’Ivoire. While these interventions did not eradicate the root causes of conflict, they succeeded in halting violence and facilitating peace talks. Nigeria, as a key player in West African peacekeeping efforts, has championed ECOWAS initiatives due to its foreign policy rooted in African cooperation and nonalignment. Nigeria’s military strength, financial backing, and historical ties to the region have positioned it as a regional stabilizer. This study aims to analyze the adequacy and efficiency of ECOMOG interventions, exploring factors that influenced ECOWAS responses to conflicts. The research methodology employs historical analysis, utilizing primary sources such as government documents and oral interviews, supplemented by secondary sources including books, journals, and archival materials. The significance of this study lies in its contribution to understanding the role of ECOWAS in regional peace-building efforts and the challenges it faces in promoting stability in West Africa.