 The following year the Cuban Missile Crisis threatened to turn the Cold War into a nuclear one . Soviet nuclear missiles were brought to Cuba , provocatively close to the US . The American president , John F Kennedy , insisted that they must be removed , and many thought that the world was on the brink of catastrophe with nuclear exchanges between the two super @-@ powers . Despite a public image of unflappable calm , Macmillan was by nature nervous and highly strung . During the missile crisis , Home , whose calm was genuine and innate , strengthened the Prime Minister 's resolve , and encouraged him to back up Kennedy 's defiance of Soviet threats of nuclear attack . The Lord Chancellor ( Lord Dilhorne ) , the Attorney General ( Sir John Hobson ) and the Solicitor General , ( Sir Peter Rawlinson ) privately gave Home their opinion that the American blockade of Cuba was a breach of international law , but he continued to advocate a policy of strong support for Kennedy . When Khrushchev backed down and removed the Soviet missiles from Cuba , Home commented : 
