There's a disturbing phenomenon happening in France that you may not have heard about. An alarming increase in anti-Christian attacks on churches, cemeteries and other distinctly Christian sites has gone largely unreported.

According to the French Ministry of the Interior, there were 875 anti-Christian incidents in 2018. The number of attacks has quadrupled between 2008 and 2019.

"This kind of thing causes real consternation," Henri Lemoigne, the mayor of a town on the English Channel, told a Catholic news source after someone vandalized a local church. "People feel that their values are under attack, even their very beings."

Richard Bernstein of RealCearInvestigations went to France to find out what may be behind this largely ignored, but unsettling issue. During his investigation, he poses this question: "Why are these attacks happening and what do they mean?"

The answer is complicated.

Many people point to an increase in Muslim migration to France as the reason for this uptick in attacks, especially after ISIS jihadists beheaded a French priest and others committed deadly terror attacks in the name of Islam.

But Bernstein says the evidence shows that Muslims only "account for a small fraction of anti-Christian crimes."

"For the majority of the attacks, we have no idea of the perpetrator," Ellen Fantini, a former federal prosecutor in New Hampshire who heads the Observatory on Discrimination and Intolerance in Vienna, told Bernstein. "It's safe to say that there are many attacks that have nothing to do with extremist groups."

When police have found and arrested the perpetrators of these attacks, they are frustrated young people, homeless, or the mentally ill. French press reports that 60% of the attackers are minors.

Many church leaders and intellectuals say the attacks are happening because there is a moral decay in France that is being expressed in direct attacks on symbols of Christianity.

French political philosopher Pierre Manent told Bernstein he partially blames the vandalism on the "crisis of the church".

"There's the impression that the church is an obstacle to contemporary life," Manent said. "And that nourishes a certain hostility. The church suffers from ill will."

Historian Jean-Francois Colosimo disagrees.

"Is it Christianophobia? No. Is it a loss of the sense of the sacred? Yes," he said.

He believes that some people who believe nothing is sacred want to destroy what was once considered sacred -- like a church. Thanks to France's rich Catholic history, there are hundreds of churches in the country vulnerable to attack.

Recently, two boys desecrated a statue of Christ and set a church ablaze in the city of Lavaur.

Lavaur priest Father Joseph Dequick says there is a move against faith in France.

"There is a mood against the church, against faith," he told Bernstein. It's a fashion to say, 'I'm an atheist.' The media are anti-Catholic. There is a discourse against the church. In France, in particular, there's an anti-clerical feeling that goes back a long time. It's not so much a religious argument as a political one. It's a reaction against the moral limitations that the church represents."

"When somebody turns a cross upside down, that's an anti-Christian expression. That represents a society that no longer transmits respect for values. It's a loss of the sense of the sacred," he added.

You can read the entire RealClear Investigations story here.