Mezue ahịrịokwu na-esonụ: United States keere òkè bụ́ isi ná nzukọ Bretton Woods na Yalta, bụ́ ndị bịanyere aka n'akwụkwọ nkwekọrịta banyere òtù ego mba ụwa ọhụrụ na nhazi ọzọ nke Europe mgbe agha biri. Ka ndị Allied meriri na Europe, otu nzukọ mba nile e nwere na San Francisco na 1945 wepụtara Charter nke United Nations, bụ́ nke malitere ịdị irè mgbe agha ahụ gasịrị. Mgbe ahụ, United States na Japan lụsoro ibe ha agha mmiri kasị ukwuu n'akụkọ ihe mere eme, Agha Leyte Gulf. United States mepụtara ngwá agha nuklia mbụ ma jiri ha mee ihe na Japan n'obodo Hiroshima na Nagasaki n'August 1945; ndị Japan
nyefere onwe ya na September 2, na-akwụsị Agha Ụwa nke Abụọ.