Strategic alliances impact foreign policy by allowing nations to enhance their security, economic interests, and political clout through collaboration. These alliances, often formed through treaties or agreements, enable countries to share resources, intelligence, and military capabilities, influencing regional and global stability. For instance, alliances such as NATO serve to deter threats and promote collective defense, which can effectively shape policy decisions regarding military engagement and diplomacy. By coordinating efforts, allied nations can present a unified front in international relations, maximizing their influence.