Answer:
It was justified because of the hostility and conflict among its many ethnic groups.
Explanation:
These were called the Palmer raids and were a part of the red scare. He did it because they were accused of being communists and anarchists, or were just too much left and liberal. This was out of fear that they might get enough people and start their own revolution in the country.
Cambodia and Lao--these neighboring countries were the path for the North Vietnamese to reach the southern parts of Vietnam more quickly.
Cambodia and Laos would be the located of the HoChi Minh Trail which was the supply line from the North to the South. Many parts of the trail were underground and difficult to get rid of. The US resorted to air strikes of the two countries which was controversial because they were technically neutral areas.
