The title of this subtle and sophisticated scholarly study is intentionally misleading. The author's intent is not to depict a Polonia semper fidelis, a “Catholic country non-pareil, ready and willing to do the bidding of the Church” (217). Rather, his purpose is to analyze and trace the complex dynamic of Catholicism in Polish politics and of Poland in the politics of the wider Catholic world in the interwar period. The complicated, three-cornered relationship of the Polish government, the Polish Church, and the Vatican ensured that tensions, misunderstandings, and disagreements were common. Neither of the dominant Polish political figures in this period, Józef Piłsudski and Roman Dmowski, was a model Catholic, and their respective parties held social and political positions that often put them at odds with Catholic policy. The Catholic clergy in Poland was, moreover, itself often divided, with respect both to domestic political and religious matters and to papal policy. Pease also treats with insight the relationship of Catholicism in Poland with Communism, Jews, Freemasons, and other religious minorities. Popes Benedict XV (d. 1922), Pius XI (1922–1939, the former papal nuncio in Poland whose Polonophilia earned him the unofficial title of “the Polish pope”), and Pius XII (from 1939) often pursued policies and methods which Polish governments and some Polish clergy found problematic and, in some instances, unacceptable. Pease's study is impressively grounded in archival and printed sources and reflects a mastery of the secondary literature. Very well written, it is an authoritative work that corrects conventional wisdom.