This is an English translation of a book that was first published in Italian four years ago, and that aroused considerable controversy in the author's native Italy.
The reasons for the controversy are plain. Emma Fattorini has used new documentation from the Vatican Secret Archive, with the "Pacelli notebooks" being a notable discovery. Eugenio Pacelli, the future Pope Pius XII, was from 1930 his predecessor's secretary of state and key framer of initiatives such as the concordat signed with Nazi Germany in June 1933.
Along with what might be telling new evidence, then, is the possibility of identifying villains and heroes. Pacelli, after all, is sometimes damned as "Hitler's Pope". By contrast, Fattorini argues that, from 1936 at least, Pius XI became increasingly determined to set the Church in open opposition to Hitler and his regime.
In 1938 and the early days of 1939, the Pope was allegedly even contemplating a drastic break with Mussolini's Italian dictatorship, despite having signed a major agreement with the regime on 11 February 1929. (Celebrated as the Lateran Pacts, this was the deal that had led Pius XI to hail Mussolini as his "Man of Providence" and brought church and state into greater unity than at any time since the Risorgimento.)
On 6 November 1938, the dying Pope would broadcast in a trembling voice his conclusion that "anti-Semitism is inadmissible. Spiritually we are all Semites", thereby simultaneously affirming Catholic objection to the practice of Nazi racism and to Italy's own recent adoption of legislation depriving the country's Jews of full citizenship.
Over Christmas and into the New Year, with the 10th anniversary of the Lateran Pacts approaching and Pius XI struggling to live until then, he prepared a still stronger statement, "the speech that was never made" of the book's title. As late as 1938, Pius XI, an authoritarian to his bootstraps, had endorsed totalitarianism, so long as all understood that "the totalitarian nature of the Church must prevail in its battle with the (lay) totalitarianisms with which it came into conflict".
But, on his deathbed ever more pessimistic and alarmed even if he was assuredly no democrat, could he have intended to launch his Church into battle with the Axis and thereby save the world from the coming greater war (whose depredations he may have foreseen)?
Can his silencing amount to a grand conspiracy?
Certainly on some of his last sleepless nights, Pius XI did make pencil notes for a wide-ranging speech. However, he died on the evening of 10 February. And papal officials, led by Pacelli, suppressed (as was their formal duty) the Pope's last thoughts, his unfinished symphony.
Indeed, they acted so thoroughly that Fattorini and others have had some difficulty reconstructing what he was trying to say.
There is plenty of interest here. Yet somehow the book does not really work. It certainly has not been helped by an over-literal translation into halting English. It has also been damaged by headed segments that are staccato in their themes and scarcely tempered into clear and subtle argument. Notable in this regard is the characterisation, or lack of it, of Pacelli, who is never really painted as the villain, but never quite explained either, except through reiterated comment that he and Pius XI constituted an odd couple.
The pontificate of Pius XI badly needs scholarly analysis (as does that of Pius XII, especially after 1945). But Fattorini's book is only a sketch of what should be done at greater length and profundity - and without resorting to a sales pitch that suggests that a melodrama that the young Verdi might have put to music was, in 1938-39, playing out in Rome.
Hitler, Mussolini and the Vatican: Pope Pius XI and the Speech that Was Never Made
By Emma Fattorini Polity, 220pp, £20.00. ISBN 9780745644882. Published 9 September 2011