A video grab made on September 30, 2015, shows an image taken footage made available on the Russian Defence Ministry's official website, purporting to show an airstrike in Syria. (AFP PHOTO / RUSSIAN DEFENCE MINISTRY)

As the Russian military commenced airstrikes in Syria, another important national institution applauded the intervention.

On Wednesday, a statement from the Russian Orthodox Church praised the Russian war effort, describing the mission to fight the jihadists of the Islamic State as a "holy battle."

"The fight with terrorism is a holy battle and today our country is perhaps the most active force in the world fighting it," said the head of the church's public affairs department, Vsevolod Chaplin, in a quote reported by Interfax news agency and translated by Agence France Presse.

Chaplin added: "This decision corresponds with international law, the mentality of our people and the special role that our country has always played in the Middle East."

To be sure, strategists in the Kremlin are probably not donning the vestments of Crusaders right now. As my colleague Andrew Roth reported earlier this week, the airstrikes are likely an opportunistic gamble by Russian President Vladimir Putin -- a move rooted more in cynicism than any religious conviction. And senior Muslim clerics in Russia have also endorsed Moscow's new war.

But Putin has anchored his political brand in religious nationalism, centered on the Russian Orthodox Church, which has emerged as a major pillar in the Russian nation-state after decades of Soviet suppression. It's a key agent in spreading Putin-friendly patriotic propaganda, from anti-gay proselytizing to backing a more muscular Russian foreign policy.

Just see this slew of images of Russian Orthodox priests blessing the state's war machines.

Putin has invoked the history of the Russian Orthodox Church as a justification for Russia's controversial annexation of Crimea, the Black Sea territory it seized from Ukraine last year. As WorldViews discussed earlier, Crimea is where, in the 10th century, one of the first great Slavic princes is said to have shed his pagan beliefs for the Orthodox Christianity of the Byzantine Empire. In a speech last year, Putin described the site of the prince's conversion as Russia's Jerusalem.

This worldview, as Chaplin indicated, extends south into the Middle East. Since the outbreak of the Syrian civil war, the Russian Orthodox Church has been outspoken about the need to protect the region's Christians and lent aid to its remaining, beleaguered patriarchates. The Middle East's Christians, according to a spokesman of the Patriarchate of Moscow in 2013, "have known for centuries that no other country would look after their interests in the same way Russia would."

This is a debatable claim, but taps into a real history. For decades, Russia's czars coveted lands then ruled by the Ottoman Empire, and framed their imperial ambitions in religious terms, as I wrote earlier:

Beginning with the Catherine the Great in the late 18th century, the Russians had framed their own conquests in religious terms: to reclaim Istanbul, once the center of Orthodox Christianity, and, as one of her favorite court poets put it, "advance through a Crusade" to the Holy Lands and "purify the river Jordan."

This rhetoric so perturbed certain 19th century Western diplomats that they tried to champion another spiritual tradition to counter Russia's dangerous zeal: Islam.

More on WorldViews

Why Russia's war is bad news for the U.S. (and why it isn't)

When the West wanted Islam to curb Christian extremism

Why Putin thinks Crimea is Russia's Jerusalem