the US was very concerned because of the fact that Cuba had nuclear missiles within range of Washington D.C. and the leader of Cuba was being heavily supported by the Russians which at this time the US were involved in a cold war with where each side was moments from launching nuclear missiles at one another.
Charles x became the King in France in the year 1757_1836
one reason is because they were a lost civilization for many years and a second reason they have mountains around them so it was very to get there.
Actually, the civil war make their relationship became much worse.
Because of the civil war, the ally has to lose a lot of resources for war supplies and equipment. This led to a situation where the allies no longer able to pay the treaties that they promisd to pay to the Sioux, which eventually ended up in conflict between the two group.