The Cuban Missile crisis brought the world to the brink of nuclear war. The two Superpowers almost obliterated the world. But the question remains whose fault was it that such a situation ever existed? The USA blamed the USSR and the USSR blamed the USA. I feel Soviets are to blame. There was also a movie based on this event from the US perspective called "13 Days". I feel the movie was historically accurate with a touch of Hollywood.
Post World War 2 saw 2 superpowers emerging trying to out do each other, the USA and the USSR. There were many close calls in the late 40's. The USA however had one advantage, The Atomic bomb.
In 1954 Russia detonated its first nuclear bomb and now could rival the USA's bargaining tool. The world now had two Super powers that had conflicting aims with weapons that could decimate the world.
The Cold War had started and the two Super powers tried to out do each other in every aspect to prove that its ideology was better.
By 1960 both sides had missiles with nuclear tipped warheads. The US had missiles installed in Turkey 150 miles from Soviet territory. This meant that the USA could strike the USSR anywhere in the globe. The Soviet Union, however did not have longer ranged missile that could hit US mainland, only Europe. Therefore under pressure to match the US it turned to its new found ally to let it install medium ranged Missiles, Cuba.
This all points so far to the US. They added missiles to Turkey trying to get the upper hand but can one really blame. During Cold war environment the Soviet Union was also trying to do the same. I feel prior to Cuba no side can be blamed.