I think that the US did what they did in this film essentially to keep everyone safe and be on top. They were going to attack Cuba, but in the very end decided not to. But because they decided not to, then Cuba had to stop all missiles and return all weapons. It is good that they came to a consensus in the end so that more trouble and war didnt occur. I think that why they decided to come to an agreement was so that they conflict and tension would stop on both parties. This then made them all happy.