Originally Posted by
G0ULI
Just as a matter of interest, you cannot renounce Polish citizenship. Polish citizenship can only be withdrawn in exceptional circumstances, by presidential order, or something like that. If you are born in Poland, that citizenship and obligations remain with you for life.
You are free to seek citizenship and reside elsewhere in the world, but you may not thereafter be allowed to return to Poland without some penalty being enforced, including imprisonment.
This is completely wrong, most consulates even have a nice and simple description of how one can go about renouncing polish citizenship (i.e. submit an application, although you then have to wait for the polish president to agree):
Obywatelstwo polskie
However it's worth noting that the obligations of polish citizenship are not exactly onerous, unlike those of the US or Eritrea (one of whom makes renouncing citizenship difficult and expensive, and the other makes it impossible).
I'm still interested in hearing whether Cuban citizenship can be renounced, but if these presumably Cuban-American dual citizens didn't follow Cuban laws, then they can't really complain.