Answer:
The Nuclear Test Ban Treaty.
Explanation: This treaty was signed in 1963, as representatives of the United States, Soviet Union and Great Britain signed the Limited Nuclear Test Ban Treaty, which prohibited the testing of nuclear weapons in outer space, underwater or in the atmosphere.
It spread several disease among the people, which where spread to Native Americans killing their population
US provided army and weapons to go against Germany, assisting the allied power to help gaining back the liberation of France on D-Day for example.
As for Japan, after the Pearl Harbor Incident, the US joined the war, defeating the Japanese in the sea battles in pacific. US also finally lead to the withdrawal and the end of WWII by dropping atomic bombs on Hiroshima and Nagasaki.
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It is d proud because he is proud
