Large regions run by a viceroy appointed by the king
Congress was completely ineffective in preventing the Civil War because the Southern states still seceded. This option is best drawn because of the fact that that in the case of the 2nd option, they did not delay the war in any way. It was only a matter of time until the war happened, and nothing could have stopped it from happening. Once the Southern states made the decision to secede, the war was inevitable.
Assuming your question is in reference to the Vietnam War, the United States got involved because of
<h2>domino theory and the policy of containment.</h2>
"Domino theory" was applied in justifying US involvement in the Vietnam War. Domino theory said that the spread of communism in Vietnam would result in other countries in the region falling like dominoes to the influence of communism.
Domino theory was a corollary to the overall policy of containment that developed as the United States' policy regarding communism after the end of World War II. George F. Kennan is known for recommending the policy of containment, which said that the best way to deal with the threat of communism was simply to try to keep it contained to the places where it already existed.
In a joint-stock company investors buy and sell shares and they own a a portion of the company. Hope this helps!