Regional/Global war?

The Vietnam War could have escalated into a regional or global war. This could have happened by Vietnam becoming completely communist. Communism would slowly move to neighboring countries and then they may allie with China. The United States didn't want to fight with China for it would escalate and they may not be able to defeat communism. This also would be the start of WWIII. Johnson worried about this happening for he was not aware of the Vietnamese history. The Vietnamese were emenies with the Chinese so they would have never became allies.
A regional war could have started when President Nixon bombed Cambodia. He bombed this country because Vietnamese communist had some bases on the eastern border of Cambodia. The bases were located there because they were protected by the Cambodian Neutrality since their establishment in 1966.  When bombing Cambodia the U.S. was at risk at starting a regional war. The Vietnam war would spread to Cambodia and other neighboring countries may get involved if the spread of war continued. This occurance also caused conflict at home when a protest was held at a university and 4 students were killed. This caused haste and more hate for the Vietnam war at home.