International alliances profoundly affect domestic security policies by shaping national defense strategies and priorities. Countries within alliances, such as NATO or bilateral agreements, often coordinate responses to external threats, influencing the allocation of resources and capabilities. These partnerships necessitate adjustments in domestic policies to align with international commitments, sometimes leading to increased military funding or intelligence sharing. Furthermore, the dynamics of global politics can drive nations to adapt their security postures based on collective interests. Understanding these alliances is crucial for analyzing how security concerns impact domestic governance and international relations.