In early February 1967 Wilson achieved what he regarded as his greatest triumph in Anglo-Soviet relations when Kosygin visited the UK. The trip was a public relations success, and was certainly more cordial than Khrushchev and Bulganin's troubled visit the previous decade. Aside from sporadic protests by Hungarian and Baltic States émigrés, the Soviet premier was generally welcomed by public and press alike. Gore-Booth was none the less incensed that Kosygin used his speech at the Guildhall on 8 February to condemn both West German ‘militarism’ and American intervention in Indochina. Crossman, hardly the most right-wing of Wilson's ministers, was astonished that when Kosygin attacked British policy on Vietnam during his visit to the House of Commons on the 9th, many Labour MPs applauded him. Yet, according to Castle, after Kosygin returned home Wilson ‘rhapsodised about the [close relationship] he had built up’ with the man he had publicly called ‘Moy starii droog’ (‘My old friend’).

Although hopes that both premiers could broker a ceasefire in Vietnam (in the form of the Phase A/B initiative) had been dashed, the prime minister stated in a televised address to the British public that his talks with Kosygin represented a ‘new high water-mark in Anglo-Russian understanding’. Wilson informed viewers that the Soviet and British governments would conclude a ‘friendship treaty’ to improve trade relations and establish a framework for increased co-operation and contacts in the fields of science, commerce and cultural relations.