Arthur M. Schlesinger, a key presidential aid during President Kennedy’s administration described the Cuban missile Crisis of October 1962 as ‘the most dangerous moment in human history’. This comment was by no means an exaggeration. Over 13 days in late October 1962 the Crisis deepened following the covert siting of offensive Soviet strategic missiles in Cuba. This all led to an unprecedented Cold War confrontation that brought the world to the verge of nuclear war.

Between June and October of that year the Soviet Union, under a clandestine operation codenamed ANADYR, shipped military equipment to Cuba that included jet bombers, strategic and tactical missiles including their nuclear warheads. In addition, over 40,000 Soviet military personnel travelled to Cuba dressed as so-called ‘civilian’ advisors. All this took place in conditions of the deepest secrecy. However, ultimately U.S signals intelligence followed up by air reconnaissance over Cuba revealed the scale of operations and the ominous implications for American security.

How and why did this the crisis happen? What preparations were in place in the U.K.’s top secret ‘War Book’? Just over six decades have passed since the Cuban Missile crisis, and with the current fraught situation in Ukraine, what lessons can we learn?