The Second Polish Republic that was pieced together beginning in 1918 out of former Polish lands and territory gained following World War I -- including Eastern Galicia, Wilno, significant parts of Wolyn, Upper Silesia, Belorussia, and a sliver of East Prussia -- was to suffer terribly, and famously, under occupation by its two hostile neighbors, Germany and the Soviet Union. Less widely recognized are the wounds that were inflicted from within.

Poland's ethnically fragmented population included substantial minorities that wanted independence. With the approach of World War II, their leaders saw opportunity in siding with either the Soviet Union or Nazi Germany, and a self destructive pattern of collaboration with hostile occupiers was born.

The roles of these minorities in the collapse of the republic and in the atrocities of "ethnic cleansing" carried out under the occupying troops and even after the war come to light in this scrupulously researched work. Significantly, some of the same strains of nationalism that propelled Poland's holocaust remain active today.