One of the leaders of the Warsaw Ghetto uprising, Yitzhak Zuckerman, later claimed that he "didn’t know a Jew who wasn’t obsessed with revenge".[6] However, very few survivors acted on these fantasies, instead focusing on rebuilding their lives and communities and commemorating those who had perished. In all, Israeli historian Dina Porat estimates that about 200 or 250 Holocaust survivors attempted to exact violent revenge, of which Nakam was a significant portion.[7] Including assassinations carried out by Mossad, these operations claimed the lives of as many as 1,000 to 1,500 people.[6]