A because the North didn't want the South to leave.
Where are the statements?
He wrote the letter because the letter warned him that a single nuclear bomb would make a mass destruction. ... It was the fact that the Nazis had the ability to develop the atomic bomb. It could destroy the whole world. So he warned Franklin D Roosevelt in his letter
The US and USSR engaged in nuclear arms race because each country was afraid of the other gaining nuclear supremacy.
It was the year of the great gold rush my dude goodluck