The United States also has Missions to the African Union (in Addis Ababa), the Organization of American States (in Washington DC), the European Union (in Brussels), the Association of Southeast Asian Nations (in Jakarta), NATO (Brussels), and many other international groups. 

How do embassies help U.S. citizens?  

Embassies help American citizens in many ways. The effects of some are in plain sight, issuance of visas to promote international visits to the United States while maintaining our border security. 

Other effects are less obvious but can have an even more direct impact: a trade agreement worked out at the U.S.   embassy  in Japan, for example, might well affect you personally in the lower cost of a car, but you would probably never know it. Close consultations with foreign governments and   international organizations  can stop an illness from becoming a pandemic. Skillful negotiations can prevent a small conflict from spiraling into a war.