The idea for a North Atlantic security organization to pool resources to fight Soviet expansionism became current after the Second World War, when many Western officials became convinced that the UN Security Council was incapable of defending Europe. Canadian diplomats such as Pearson pushed hard for the idea and in 1947 Louis St. Laurent, then Minister for External Affairs, brought forward a motion for such a security organization at the UN General Assembly.
Canadian diplomats pressured lukewarm US officials to commit themselves formally and openly to the defence of Western Europe. Pearson, as Ambassador to the US and then as Minister of External Affairs, inserted a clause (dubbed the "Canadian Article") into the agreement which broadened the terms of a military accord to include the promotion of economic well-being and social justice among member states. Unfortunately, little came of it. Nonetheless, Pearson felt that Canada had played a consequential role in NATO's establishment and considered its signing one of the most important accomplishments of his public life.
