In the wake of the Soviet armies during 1944–45 came police units. In Poland the communist Office of State Security (Urzad Bezpieczerstwa Publicznego, UB) refilled former Nazi camps and prisons with civilians, many of whom were Germans innocent of any offence other than that of being German. Somewhere between 60,000 and 80,000 died as a result of UB behaviour in the camps and prisons; victims were beaten, tortured, starved, killed. One of the only researched UB units is that which operated in Upper Silesia, particularly around the town of Gliwice, about 50 miles north of the Czechoslovak border; the town had formerly been in Germany, and had been known as Gleiwitz. All of the commanders of this UB unit were of Jewish origin, as were three-quarters of their men. John Sack, who drew particularly on the oral evidence of Jews, Germans and Poles from the region, called his bleak study of Gliwice An Eye for an Eye (1993). Even recognising that the Jews were ‘provoked’, Sack, himself a Jew, found it painful to acknowledge that Jews were responsible for the deaths of ‘not Nazis … but German civilians, German men, women, children, babies, whose “crime” was to be Germans … I suspected that some Jews would ask me,“How could a Jew write this book?” and I knew the answer must be “No, how could a Jew not write it?”' (pp.x–xi).