Why do few nations dominate European cinema so much?

During the Silent Era, the biggest producers of quality films were Germany, France, Sweden. Russia toward the end (the country did have issues in the late teens early 20's). German and French cinema rivaled Hollywood. And foreign language movies were more accessible to American audiences. Just a matter of translating and making new intertitles. But Hollywood had more money and adapted to sound quicker. German film was wrecked by the Nazis, forced to make propaganda films. Ironically, Britain never mad a lot of quality silents.