The Nazi's Germany and the URSS are going to invade Poland, we signed a non-agression pact
Germany and the URSS anexxed Poland, but this made that UK and France got into war with Germany
France was also defeated.
Germany started attacking the USRR
Why Germany is attacking us?!!! Hitler is breaking the non-agression pact.
But the USRR took Berlin  and made surrender to Germany
Japan attacked the US navy base of Pearl Harbour that made the USA entered into war, but finally they launched a nuke bomb to Nagasaki and Hiroshima in Japan