The Polish nation sent 28,000 of its best soldiers to invade a sovereign state and,
Neither Poland nor Czekoslovakia were a sovereign states at the time.
with the exception of one brave man, not a single Pole protested.
Really? And you were there and you saw every single Pole not protesting?
Let's see:21 VIII interwencja zbrojna Układu Warszawskiego w Czechosłowacji, uczestniczy w niej ponad 20 tysięcy żołnierzy WP; w całej Polsce liczne protesty - odnotowano dziesiątki przypadków pojawienia się ulotek i napisów na murach
August 21 - intervention of Warsaw Pact force in Czechoslovakia, over 20 thousand Polish troops participate, numerous protests all over Poland - dozens of cases of leaflets and writings on walls
A popular slogan in Poland at the time was "Polska czeka na Dubèeka" czy "Czekamy na swego Dubèeka" (Poland is waiting for her own Dubèek). Poland's participation in the invasion was and is widely viewed by Poles as dishonor to the Polish military uniform and symbols.
read more here, and translate to the best of your skills how no Poles but one allegedly, did not protests against the invasion.
Or at least, kindly, translate this letter of protest by Polish students of all Wroclaw universities:
again, do not sensationalize and twist facts as you see fit.