structural:expansion
United Kingdom and France

Trudeau attached little importance to relations with the United Kingdom. While he shot down a suggestion by one of his ministers to turn Canada into a republic in 1968, he treated the monarchy with a certain bemused contempt. Britain's 1973 decision to join the European Economic Community (EEC) confirmed Trudeau's view that the UK was a declining power that had little to offer Canada, while the way that Japan had replaced Britain as Canada's second-largest trading partner was taken as further confirmation of these views. However, Trudeau was attached to the Commonwealth, believing it was an international body that allowed Canada to project influence into the Third World; he noted it was one of the few bodies that allowed leaders from the First and Third Worlds to meet on a regular basis. Although France was no longer as supportive of Quebec separatism as it had been under President Charles de Gaulle in the 1960s, the way that French politicians expressed the idea of a special Franco-Quebecois bond as opposed to a special Franco-Canadian bond throughout the 1970s led to tensions with Paris.

In 1970–71, the Commonwealth was threatened with a split as a number of African members, supported by India, denounced Britain's policy of selling arms to apartheid South Africa, which the UK argued was necessary because South Africa was not only one of the world's largest gold producers, but its government was anti-Communist and pro-Western. The Wilson government had imposed an arms embargo on South Africa in 1964, which the new Conservative Heath government ended in 1970. A number of African Commonwealth nations led by Kenneth Kaunda of Zambia and Julius Nyerere of Tanzania threatened to leave the organization if Britain continued with arms sales to South Africa. When British Prime Minister Edward Heath visited Ottawa in December 1970, his meetings with Trudeau went badly. In what was described as a "no holds-barred" style, Trudeau told Heath that the British arms sales to white supremacist South Africa were threatening the unity of the Commonwealth. At a Commonwealth summit in Singapore between 14 and 22 January 1971, Trudeau argued that apartheid was not sustainable in the long run given that the black population of South Africa vastly outnumbered the white population, and it was extremely myopic for Britain to be supporting South Africa, given that majority rule in South Africa was inevitable. However, Trudeau worked for a compromise to avoid a split in the Commonwealth, arguing that it needed to do more to pressure South Africa to end apartheid peacefully, and saying that a "race war" in South Africa would be the worse possible way to end apartheid. The conference ended with a compromise agreement in which Britain would fulfill its existing arms contracts to South Africa but henceforth sell no more weapons to the country; ultimately, the British only sold South Africa five attack helicopters. Singaporean Prime Minister and conference host Lee Kuan Yew later praised Trudeau for his efforts at the summit to hold the Commonwealth together, despite the passions aroused by the South African issue.