What were the causes of the Cuban missiles crisis? How was the crisis resolved and what were its consequences?

When Fidel Castro seized the power from the dictator, who was corrupt and backed by America marked the entry of Cuba into the Cold War. He nationalised the American owned estates and factories. This worsened the relations with USA and in January 1961, USA broke the diplomatic relations with Cuba. This made the relation of Cuba with USSR stronger and Russians increased the economic aid.
America repeatedly troubled Cuba first by sending small force to overthrow the regime but failed then sank Cuban ships, destroyed the installations on islands and American troops carried out invasion. Then Castro asked USSR for military help. USSR decide to install missile launchers in Cuba aiming at USA creating threat to major American cities. The photographs taken by spy planes confirmed the installations.
The situation was so tense that the Secretary General of UN appealed to both to restraint. They were so near to the outbreak of nuclear war as USA had threaten to go with a war on USSR if they did not back off. The first move was taken by USSR and called back the ships that were carrying missiles and destroyed the installation site in Cuba. In return USA agreed not to invade Cuba in future and removed the Jupiter missiles installed in Turkey to threaten USSR.
The consequences of the crisis was a hotline was developed between USSR and USA to have swift consultations. And in 1963, both signed a Nuclear Test  Ban Treaty to carry out nuclear testing underground. Till date USA has not intervened in Cuba.

Topics: GS-I: World Wars, Cold War and Other Major Events of 20th Century