Original sentence: Solidarity's survival meant a break in the stance of the communist Polish United Workers' Party, and was an unprecedented event not only for Poland, a satellite of the USSR ruled by a one-party communist regime, but for the whole of the Eastern bloc
Edited sentence: Solidarity's survival meant a break in the hard-line stance of the communist Polish United Workers' Party, and was an unprecedented event not only for Poland, a satellite of the USSR ruled by a one-party communist regime, but for the whole of the Eastern bloc