Explain why the usa was concerned about soviet missiles in cuba

The United States was very much concerned about the Soviet missiles in Cuba because they was worried that they could use them against the United States.Both the United States and the Soviet Union does not believe each other there was already a lack of trust then this happen which raised the tension between the United States and the Soviet Union.And, when the United States came to know about the Soviet missiles in Cuba then this created serious tension between U.S and the soviet union.