Poland was part of the Russian Empire from 1900 to 1915. The German's annexed all of Poland, much of Belarus and the Baltic States in the Treaty of Brest-Litovsk of Feb 1918. Poland declared its independence after Germany signed the Armistice of 11/11/1918. It had bad relations with all of its neighbors. Poland grabbed Vilnius, the traditional capital of Lithuania. The Curzon Line, proposed by a British diplomat proved to be an unacceptable border between Poland and Russia. The Soviet Union tried to reincorporate Poland into the USSR, but their bid failed in the Battle of Warsaw. In the wake of that battle, Poland pushed the Red Army back beyond the Curzon Line and ended up taking the western half of Belarus.
Czechoslovakia incorporated a small provenance called Teschen, which had a slight majority of ethic Poles, living in a small area of 80,000 people. Poland had frosty relations with Czechoslovakia over this rather minor issue. Poland did have an alliance with France. Although, by the time war broke in 1939, the Little Entente France put together with Belgium, Poland, Yugoslavia and Rumania had broken down. Belgium, Yugoslavia and Rumania all remained neutral when Poland's biggest regional difference broke out in war.
The framers of Versailles wanted the new state of Poland to have access to the sea and carved the "Polish Corridor" between Germany and east Prussia. This was a built in regional dispute, Germany would want the Polish Corridor back, once they threw off the shackles of the Versailles Treaty.
Sources: "The German Wars" by D J Goodspeed
"The Rise and Decline of Great Powers" by Paul Kennedy