According to Leopold Pallu, why were the Vietnamese so successful

Due to their knowledge and tactics.

Explanation:

According to Leopold Pallu, the Vietnamese were so successful against United States Army because they had very good and important knowledge about the forests and jungles and were able to protect their supplies from damage through various methods. The Vietnamese knows about their lands and this factor gave them an ultimate advantage against U.S troops so that's why the Leopold Pallu says that Vietnamese were so successful in the war.

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