Answer:
Failure of Operation Rolling Thunder: The bombing campaign failed because the bombs often fell into empty jungle, missing their Vietcong targets. ...
Failure of Search and Destroy (My Lai Massacre): Search and Destroy missions were often based on poor military intelligence.
Step-by-step explanation:
Support of China /USSR: One of the most crucial reasons for the defeat of the USA was the unflinching support of China and the Soviet Union to the North Vietnam. Despite best efforts of the USA, there was no interruption of supplies of food and war material for the Vietcong .
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