In Jan Toporowski's interesting review of Minsky' recently-published PhD thesis, he mentions in passing that the reason Minsky went to Harvard after serving in World War II, rather than returning to the University of Chicago, was that his Chicago mentors were no longer there. One, the liberal Henry Simons, "had committed suicide in despair at the onset of Keynesianism"; the other, Oskar lange, had returned to post-war Poland to take up a series of senior positions in the new government there; among others, as Poland's first post-war ambassador to the United States. Both, I guess, deserve credit for following their principles all the way to the end.
It's the case of Lange that really intrigues me. There doesn't seem to be a biography of him available in English, but according to this admiring obituary in Econometrica, he was a member of Parliament and of the Central Committee until his death in 1965, and held various other high offices, through the postwar reconstruction through the height of Stalinism and into the post-1956 reform period; he also taught the whole time at the University of Warsaw and published eight books. A full and successful career, in short.
Is there any other figure of comparable stature who made a similar move from a respected, prominent position in the US (or Western Europe) to a respected, prominent position in the Eastern Bloc? I certainly can't think of any.