The 1960s saw several major international incidents, including the U-2 incident and Bay of Pigs Invasion. The Bay of Pigs Invasion in 1961, which aimed to overthrow Fidel Castro, failed due to problems such as Cuban air defenses remaining intact and a lack of uprising by Cuban citizens. In 1962, the Cuban Missile Crisis nearly resulted in nuclear war between the US and Soviet Union over Soviet missiles in Cuba but was resolved through negotiations. In the aftermath, a direct communication link was set up between the US and Soviet leaders and treaties limiting nuclear testing were signed.