that this stuff all grows out of.
The foundation of mid-century European Fascism was in conservative elements of the Catholic Church. They were deeply concerned about social disintegration following the Great War and also, having seen the destruction of the Eastern Church in the recent Russian Revolution, saw the Soviet Union as the primary enemy.
The regrettable excesses aside, that remained fairly static through the war and after and the American OSS was pivoting to the next war well before the surrender. James Jesus Angleton was sent in as OSS station chief in Rome and traded safety for Nazi Catholic war criminals for the use of the world's best intelligence network and other lesser advanages like an alliance with the Italian Mafia (Italian Communist guerillas were the most effective irregulars of the war- and deeply popular for it- and a quiet civil war went on for a couple more decades).
The grand coup came when the OSS' descendant, the CIA, managed to install a long term operative- Bishop Karol Wojtyla of Poland, on the throne of St. Peter, which ultimately led to the breakdown of the Soviet Empire- obviously with a great many other machinations going unrecognized.
That represented the high point in Roman Catholic influence in the USA but the legacy remains through sleeper organizations such as The Federalist Society that seek to advance a reactionary social and economic agenda and defend the opacity and immunity from civil authority enjoyed by the Vatican for more than a millennium.
