Swiss Guards salute Pope Francis as he arrives for the opening session of the CEI, Italian Episcopal Conference, at the Vatican on May 16. (Alessandra Tarantino/AP)

In an interview with a French Catholic newspaper published this week, Pope Francis sent yet another shot across the bow of Europeans grandstanding over the threat of Muslim immigration.

When asked by a journalist from La Croix about fears of Islam and terrorism, the pontiff suggested it was not productive to think of Islam as a threat and pointed to its shared roots with Christianity.

“It is true that the idea of conquest is inherent in the soul of Islam," he said. "However, it is also possible to interpret the objective in Matthew’s Gospel, where Jesus sends his disciples to all nations, in terms of the same idea of conquest."

It can be inferred that the pope is likening the Islamic principle of "jihad" — sometimes narrowly construed to mean holy war, but more accurately understood as a kind of spiritual struggle — with the Christian proselytizing mission.

Over the past year, Pope Francis has placed himself at the center of political conversations roiling the West, championing the plight of refugees while calling for more tolerance within European societies. In April, he journeyed to the Greek isle of Lesbos and visited a migrant detention center. On his return, he brought home with him a dozen Syrian refugees.

"May all of our brothers and sisters on this continent, like the good Samaritan, come to your aid in the spirit of fraternity, solidarity and respect for human dignity," he said in an address to migrants on Lesbos.

In the interview with La Croix, the pope also appeared to decry the rhetoric of a clash of civilizations, which has proliferated among an ascendant far-right on the continent and animated the politics of the U.S. presidential election.

"Yes, Europe has Christian roots and it is Christianity’s responsibility to water those roots," Pope Francis said. But, he insisted, "this must be done in a spirit of service" rather than the ultra-nationalism on view in countries from Hungary to Germany to Britain.

"When I hear talk of the Christian roots of Europe, I sometimes dread the tone, which can seem triumphalist or even vengeful. It then takes on colonialist overtones," Pope Francis said.

He also congratulated London for electing a Muslim mayor, Sadiq Khan, and hailed Khan's success as an example of Europe's capacity for integration. He lamented the ghettoization that spawned the jihadists who unleashed death and mayhem in Paris and Brussels.

Khan is in the midst of a war of words with Donald Trump: The newly elected mayor this week offered to "educate" the Republican presidential front-runner about the ability of Muslims to embrace liberal values.

"In Brussels, the terrorists were Belgians, children of migrants, but they grew up in a ghetto," Pope Francis said. "In London, the new mayor took his oath of office in a cathedral and will undoubtedly meet the Queen. This illustrates the need for Europe to rediscover its capacity to integrate."

That's desperately needed, the pontiff suggested, because Europe faces a declining birthrate and "a demographic emptiness."

Though sometimes labeled as a "progressive" leader of the church, Pope Francis sounded very much the member of an ancient institution when hailing European integration. After celebrating Khan, he compared the moment to the 6th century A.D., when Pope Gregory the Great "negotiated with the barbarians."

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