Solidarity, the free Polish trade union that emerged in 1980, acted in close alliance with the Roman Catholic Church. The union's struggle for human dignity and freedom became a question of national redemption and often used religious symbols and rituals. Although one can argue whether Pope John Paul II was personally the fulcrum of revolt, Solidarity and the demise of Polish Communism are hard to imagine without him. Not surprisingly, the Polish security forces made vigorous efforts to penetrate the Polish Catholic Church, eventually enlisting as informants some 15 percent of the clergy. Recent revelations of extensive collaboration by priests, notably in Father Tadeusz Isakowicz-Zaleski's acclaimed book, provide a valuable correction to the historical record but do not greatly detract from the overall image of the Church as having resisted Communism. The Church, among other things, served as a refuge for many in the darkest moments of the Communist era and helped to force change by throwing its support behind Solidarity.