Respuesta :
I think the correct answer would be the second option. The Soviet Union joined the allies because Hitler had broken a pact and attacked. The pact was called the German-Soviet nonaggression pact. This pact was regarded by Hitler as a tactical move. It was signed on the year 1940 and after a year Hitler attacked the Soviet Union.
The soviet Union joined the Allies during WW II because Hitler had broken a pact referred to as a non aggression pact and attacked.
The Non-Aggression Pact
The non-aggression pact or neutrality pact was a treaty between Germany and the Soviet Union that includes a promise by the signatories not to engage in military action against each other.
Adolf Hitler broke the Non-aggression pact during WWII and this prompted the soviet Union to join forces with the Allies.
Learn more about WWII at https://brainly.com/question/11378857