Nuclear weapons technology was developed during the Cold War, which makes it possible to launch missiles across vast distances and wage wars that create exponentially more damage than before.
Fall to communism
The U.S. government considered its involvement in the war as a way to prevent a communist takeover of South Vietnam. This was part of the domino theory of a wider containment policy, which aimed to stop the spread of communism.
The correct answer is - a civil war began immediately.
After Bosnia and Herzegovina got out of Yugoslavia and the communism came to an end, a civil war started on its territory, and it was caused by the Serbians and Croatians, with the Bosnian Muslims in between, and it all escalated to a war and genocide, in which the country was left in ruins and lots of people lost their lives.