The famous diplomat who played a significant role in establishing peace treaties post-war is George C. Marshall. As a U.S. Secretary of State, he is best known for the Marshall Plan, which aimed to aid European recovery after World War II. His efforts not only helped rebuild war-torn nations but also fostered political stability and economic prosperity, preventing the spread of communism. Marshall’s diplomatic initiatives were characterized by his belief in cooperation and collective security, effectively laying the groundwork for modern American foreign policy and establishing him as a key figure in international relations.