Fear of consequences keeps defectors silent
Where leaving carries a penalty, people who want to go stay put, and those who have left avoid saying exactly why others don't follow. Unspoken threats do their work through what goes unsaid.
Performance

A close journey through Cuban gyms, coaches, state amateur sport, and Olympic aspiration shows how a national boxing culture produces fighters.
Where leaving carries a penalty, people who want to go stay put, and those who have left avoid saying exactly why others don't follow. Unspoken threats do their work through what goes unsaid.
Boxing done well rests on skill and strategy rather than brute force. Its practitioners enjoy it as a craft and can discuss its details at length.
Under poverty and endless official rules, people get by through humour, compassion, shared drink and quietly ignoring regulations. Breaking small rules becomes a survival skill rather than a moral failing.
When a state outlaws professional sport and pours resources into mass participation and facilities, the talent that would have chased money flows into an amateur system instead. That system can then make the country an amateur superpower, with Olympic results held up as proof that the whole policy works.
When one institution controls an athlete's whole career, it also controls whether they may leave, who goes with them, and what happens to them once they stop being useful. Loyal servants can end up retired, broke and bitter, and permission to emigrate may be granted to the athlete but withheld from his spouse.
Beating the dominant neighbour at something it considers its own can release long-held feelings of national inferiority. Athletes fight harder because they want to take from the rival something it believes it owns by right.
Escaping a state-run amateur system doesn't bring a fair contest: professional judging can favour commercial interests over the fighter in the ring. Amateur competition, for its part, carries its own murky international politics.
Those who run a national sports system explain its success through the wider culture, for instance linking skill in the ring to a people's love of dancing. Such explanations make the sport part of national identity, even when the causal claim is shaky.