the only tribes that did not have permanent settlements were the ones who chased their food. like the blackfoot tribe. because of this since food sources like buffalo were always on the move, they couldn't stay in one place. however with the advancements made in farming, they were able to stay in one place usually close to a river and grow their food while only hunting nearby wild life.
To prevent the spread of communism in Southeast Asia is why did President Kennedy get the United States involved in the Vietnam War so the reason was the usage of containment policy.
