That is an interesting scenario. And of course nobody can prevent abuse of open source projects if legal institutions are abolished or held at metaphorical gunpoint, but even in that case the actual open technology would be still open to others. It would just limit the contributors that contribute back to the project. If x country hard forks the existing project, ignores the license, stops contributing back and starts working on it solo, it would get isolated pretty fast. Nobody wants to do business in a country that offers no legal protections. We even have a recent example of that happening. Russia nationalized a few international businesses and as a result many companies just pull out of the country. Yandex (who was owned by Dutch mega-company), sold out to Russia for half of what they were worth since the risk to keep operating was too high.

Open source license abuse is nothing new, big companies do that all the time since small volunteer contributors doesn't have the capital to force compliance.