Amid concerns that President Trump is losing interest in a peace pact between Russia and Ukraine, could the new pope be stepping into the breach? “Pope Leo suggested it and if he’d like to have the talks at the Vatican, I can’t think of a better place,” Mr. Trump said Tuesday. So far, the idea of a papal peace is merely notional. Prime Minister Meloni, though, allows that Italy “viewed positively” the idea and would “facilitate contacts and work towards peace.” 

Leo’s apparent interest in diplomacy is already generating attention in the press, in part because it marks a decisive break from the approach by his predecessor, Francis. The prior pontiff shied from blaming Moscow for the war, Le Monde reports, “refusing to acknowledge the responsibility of Vladimir Putin and Russia.” Francis aimed to foster dialogue, and “even expressed a desire to see Vladimir Putin first before traveling to Kyiv,” Le Monde adds.

By contrast, Leo seems keen to enter the fray, offering the Vatican as a venue for talks and, as Polish broadcaster TVP reports, “meeting with Ukrainian leaders, calling for direct negotiations, and placing Ukraine at the centre of his peace appeals.” President Zelensky touts Leo’s “willingness to serve as a platform for direct negotiations,” even as Bloomberg warns of the new pope entering “an intractable conflict that has no clear end in sight.”

The new pope’s pacific overtures stir echoes of an earlier pontiff’s efforts to end a bloody conflict. That démarche emerged in November 1917 when Pope Benedict XV issued, in French and Italian, a Peace Note that would become “the most famous episode of a pope unjustly forgotten today,” historian Patrick Houlihan reports. While Benedict’s call for a negotiated peace failed to make headway, it influenced President Wilson’s Fourteen Points.

Benedict had acceded to the throne of St. Peter in the early innings of the war that he decried as a “useless slaughter” and the “suicide of civilized Europe.” As early as November 1914 he was urging an end to the fighting, even as European leaders ignored the papal pleas. Part of the problem, Mr. Houlihan avers, was that “the Holy See had an ambiguous diplomatic position,” having only recently lost its Italian territories, and it was unclear which side the pope favored.

The pope’s proposals included calls for “reciprocal reduction of armaments,” Mr. Houlihan says, along with “international arbitration” and freedom of navigation. More contentiously the pope asked the Great Powers to renounce war indemnities, while also withdrawing from occupied lands and approaching “with conciliatory spirit” postwar territorial demands. These proposals would prove a bridge too far for the warring nations.

Germany’s military high command, for one, “refused to give up territory in Belgium,” Mr. Houlihan writes. Similarly, “France and Britain would not consider peace plans before German soldiers withdrew from Belgium and France,” he adds. There are parallels with today’s stalemate, as Moscow aims to keep the Ukrainian territories it has captured, and Kyiv refuses to accept the loss of Crimea. 

While World War I was stalemated when Benedict issued his letter, the principals hesitated to make peace in part because so many soldiers and civilians had already died. Yet the final year of the war, which ended in 1918, proved to be the most cataclysmic of all, as dynasties toppled across Europe and the Bolsheviks solidified power in Russia. Benedict’s papal peacemaking, in retrospect prescient, failed to yield results. Could his successor Leo’s efforts fare better?