Soviet focus had been on cheaper, larger-yield atmospheric tests). For this reason, many in the Soviet weapons industry argued that a partial ban would give the US the advantage in nuclear capabilities. Khrushchev would later recount that he saw test-ban negotiations as a prime venue for ameliorating tensions after the crisis in Cuba. Shocked by how close the world had come to thermonuclear war, Khrushchev proposed easing of tensions with the US. In a letter to President Kennedy dated 30 October 1962, Kurshchev outlined a range of bold initiatives to forestall the possibility of nuclear war, including proposing a non-aggression treaty between the North Atlantic Treaty Organization (NATO) and the Warsaw Pact or even the disbanding these military blocs, a treaty to cease all nuclear weapons testing and even the elimination of all nuclear weapons, resolution of the hot-button issue of Germany by both East and West formally accepting the existence of West Germany and East Germany, and US recognition of the government of mainland China. The letter invited counter-proposals and further exploration of these and other issues through peaceful negotiations. Khrushschev invited Norman Cousins, the editor of a major US periodical and an anti-nuclear weapons activist, to serve as liaison with President Kennedy, and Cousins met with Khrushchev for four hours in December 1962. Cousins' secret mission was aided by Pope John XXIII, who served as an intermediary; officially, Cousins was traveling to Rome on a personal basis, but from the Vatican he continued to the Soviet Union. Through Cousins' shuttle diplomacy in 1962 and 1963, the pontiff remained at the center of negotiations and helped ease misunderstandings between the two world leaders. Kennedy's response to Khrushchev's proposals was lukewarm but Kennedy expressed to Cousins that he felt constrained in exploring these issues due to pressure from hardliners in the US national security apparatus. However Kennedy pursued negotiations for a partial nuclear test ban. On 13 November 1962, Tsarapkin indicated that the Soviet Union would accept a proposal drafted by US and Soviet experts involving automated test detection stations ("black boxes") and a limited number of on-site inspections. The two sides disagreed over the number of black boxes, however, as the US sought 12–20 such stations and the Soviet Union rejected any more than three. On 28 December 1962, Kennedy lowered the US demand to 8–10 stations. On 19 February 1963, the number was lowered further to seven, as