Briefly explain ONE way in which United States involvement in world affairs changed

They stopped being isolated from world affairs

Explanation:

America used to be so isolated from the rest of the world 1945 was the year that the second world war ended. After the war the US became of the world powers and they became more involved in international affairs.

The US influences the global world economically, politically, technologically and also in military strength.

Economically the US since 1945 has had great influence on the world through trading and it's economic policies. It is the greatest and the most important destination for exports for a lot of countries globally