The two wars are connected because Vietnam War is one of the many proxy wars of the Cold War between the United States and Soviet Union. Both countries fought in the war without directly fighting each other. Instead, the Soviet Union puppet government North Vietnam and the Viet Cong fought against south South Vietnam, and American troops fought to avoid North Vietnam taking over the region.
The united states dropped the worlds first attomic bomb over the city of Hiroshima in Japan and this explosian wiped 90% of the population a dlater killed many around 80,000+ were dead.