ROME – By tradition, both the United States Senate and the College of Cardinals have been a sort of Country Club in which members, whatever their disagreements, treat one another with courtesy. That culture of civility disintegrated long ago in the Senate, and if Cardinal Joseph Zen has anything to do with, it may not be long-lived in the Church either.

On Oct. 7, Zen, the retired bishop of Hong Kong, posted a long reflection on the Vatican’s approach to China on his personal blog, in which – there’s really no other word for it – he eviscerated fellow Cardinal Pietro Parolin, the Vatican’s Secretary of State and the man largely responsible for the Vatican’s 2018 deal with Beijing on the appointment of bishops.

“Parolin knows he himself is lying. He knows that I know he is a liar. He knows that I will tell everyone that he is a liar,” Zen wrote, adding for good measure that he doubts Parolin even has any faith.

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For those who’ve been following the debates over the Vatican’s 2018 deal with China, it’s well known that Zen and Parolin represent opposing approaches. Zen is a hawk, Parolin a dove; Zen believes in courageous witness, Parolin in patient diplomacy.

Yet the language by Zen in his new post is about more than policy. It’s exceedingly personal, accusing Parolin of dishonesty, putting ambition over principle and acting in bad faith.

To call such a public blast by one cardinal against another “rare” is to traffic in understatement. To find any sort of precedent we have to go back a decade, and a public conflict between Cardinal Christoph Schönborn of Vienna, Austria, and Italian Cardinal Angelo Sodano, the Secretary of State under St. John Paul II and, at the time, the Dean of the College of Cardinals.

During a session with Austrian journalists in April 2010, as a new round of the clerical sexual abuse crisis was cresting across Europe, Schönborn made two explicitly critical remarks about Sodano.

First, Schönborn said that Sodano blocked an investigation of sexual abuse claims against the late Cardinal Hans Hermann Groër of Vienna. Groër, who died in 2003, had been accused of abuse by several former novice monks at the Benedictine abbey in Austria where he once served as abbot. The charges against Groër became public in 1995, producing a major crisis in the Austrian church. Three years later, Schönborn led a group of Austrian bishops who announced they were “morally certain” of Groër’s guilt.

Second, Schönborn said that comments by Sodano during the Vatican’s 2010 Easter Sunday Mass, in which Sodano compared attacks on Pope Benedict XVI for his handling of the crisis to “petty gossip,” had done “massive harm” to victims of sex abuse.

To this day, it remains unclear whether Schönborn thought he was off the record in that conversation, though perhaps it doesn’t really matter. The idea that you could raise questions with reporters about the integrity of a fellow cardinal and not expect it to leak is just dumb, and Schönborn, a multi-lingual Dominican and arguably the finest theologian in the college, is anything but.

In response, Schönborn was summoned to the Vatican for a kiss-and-make-up session presided over by Benedict XVI, after a Vatican spokesman pointed out that under the terms of Canon 1405 of the Code of Canon Law, it’s the exclusive prerogative of the pope to judge a cardinal, not another member of the club.

(That canon, by the way, is relevant again today in the case of Cardinal Angelo Becciu, the former “substitute” in the Secretariat of State accused of various forms of financial corruption. The question is, when Pope Francis demanded Becciu’s resignation from his rights as a cardinal but not the red hat itself on Sept. 24, does that mean canon 1405 no longer applies and Becciu is thus subject to the jurisdiction of a Vatican tribunal?)

When Schönborn and Sodano came together on June 28, 2010, a Vatican statement afterwards suggested Schönborn had acknowledged that Sodano had the “same feelings of compassion” for victims of sexual abuse, and the same “condemnation of evil,” as Benedict XVI. It did not, however, address Schönborn’s claim about the role Sodano had played in the Groër case, essentially allowing it to stand.

It seems highly improbably things will play out the same way this time around.

For one thing, Sodano was no longer the Secretary of State when Schönborn spoke, and Benedict XVI may have felt Sodano no longer had the heft to handle things alone. Parolin, however, is at the height of his powers, and can certainly take care of himself.

For another, Zen was just in Rome last week seeking an audience with the pontiff, so had Francis wanted to issue a fraternal correction in person, he certainly could have. The pope’s approach to such things, however, is generally to freeze his critics out – witness his non-response to the “dubia cardinals” as the premier case in point.

In all likelihood, Francis will stay out of it; Parolin, ever the diplomat, will refuse to respond in kind, and won’t take any action; and Zen, fueled by a strong sense of conviction, won’t back down.

In other words, probably there will be no dramatic showdown in Rome to hash things out, followed by a face-saving public statement. Instead, the war of words – admittedly one-sided, but then Parolin’s response actually comes in pursuing détente with China regardless of what Zen says – will continue. It may be hard to imagine how much more forceful Zen could be, but where there’s a will there’s also usually a way.

In other words, nothing about the Vatican’s policy on China may be affected by any of this. The College of Cardinal’s run as a polite society, on the other hand, may be very much in jeopardy.

Follow John Allen on Twitter at @JohnLAllenJr.