Russia got the bomb
Spying was ramped on both sides.
There was an arms race and it was open, which was the main reason for Eisenhower warning against the Military Industrial complex. The military was just becoming far too powerful.
Volunteer soldiers. In America, there are no enlisted men, only citizens willing to give up their lives for their country. But during a serious war, there can be soldiers being deployed against their will so that there are more soldiers to help during the war.