Why was the US allied with the USSR during WW2?​

they needed each other to defeat a tough enemy. "a shared realization that each country needed the other to defeat one of the most dangerous and destructive forces of the twentieth century."

Explanation:

nothing certain is known about what happened, but it seems that the country declined gradually, perhaps due to bad government, or, more likely, due to a series of bad harvests, which resulted in widespread and recurrent famine.

b: the establishment clause  

b: socialism