en.wikipedia.org/wiki/Pilsudski
At a meeting in Paris in 1914, PiĆsudski presciently declared that in the impending war, for Poland to regain independence, Russia must be beaten by the Central Powers (the Austro-Hungarian and German Empires), and the latter powers must in their turn be beaten by France, Britain and the United States
In Frist World War majority of Poles were fighting on Central Powers side agains Russia ... when Russia was beaten Poles changed the side (on French) or stoped fighting.
He was succesful, Poland regained independence.