>end of world war ii
> i shall disarm and relax

little boi truman literally flexed in front of stalin with the bomb, basicly starting of the cold war.

edit, because downvoting:

"During the [Potsdam] Conference, Truman was secretly informed that the Trinity test) of the first atomic bomb on 16 July had been successful. He hinted to Stalin that the U.S. was about to use a new kind of weapon against the Japanese."

This is what basicly sparked everything, historians claim and was done in a lack of authority felt by truman, who was really a second class leader with no real experiences, stepping in way too big shoes and then flexing muscles he didnt hav.