Back in 1924, the nominee of the Progressive Party for Vice President, Burton Wheeler, hit on a novel gimmick to call out Republican President Calvin Coolidge on the campaign trail. Instead of just complaining about the incumbent’s unwillingness to engage his challengers, Wheeler set up an empty chair on stage and pretended as if Coolidge actually were in the room.

Ever since, the “empty chair” has been a symbol of a critical player’s absence from a conversation, usually with the suggestion that he or she has some explaining to do for not showing up.

Had there had been such an empty chair at last Saturday’s ecumenical summit in Bari, Italy, hosted by Pope Francis with the aim of praying for peace in the Middle East, it obviously would have been directed at Patriarch Kirill of Moscow, head of the Russian Orthodox Church and the day’s most glaring no-show.

Granted, Kirill did send what a Vatican aide described as a “beautiful letter” in response to the pope’s invitation and also dispatched a senior representative in the person of Metropolitan Hilarion, in effect his top deputy. Nonetheless, Saturday’s event was styled as a gathering of patriarchs from Eastern churches, and the absence of the leader of the denomination that represents roughly two-thirds of all the Orthodox Christians in the world still was keenly felt.

(In fairness, he wasn’t the only Orthodox leader to give Bari a miss. The Greek Orthodox Patriarchate of Antioch didn’t even send a representative, presumably because of a policy of not attending any event where the Patriarchate of Jerusalem is represented. The two churches are locked in a dispute over which one has jurisdiction over Qatar.)

Kirill’s decision not to attend the July 7 gathering in Bari was especially striking given that, in a sense, the whole thing was his idea.

In mid-April, Kirill phoned Francis the day after a coalition formed by the United States, the United Kingdom and France bombed military targets in Syria suspected of harboring chemical weapons. At the time, the Russian Orthodox leader told reporters he had stressed to the pope the importance of Christians coming together to try to stop the bloodshed.

“We spoke about how Christians should influence the events with the scope of putting an end to the violence, ending the war, preventing even more victims,” Kirill said.

“We have come forward with this initiative, knowing that the Christians cannot remain on the sidelines seeing what is happening in Syria,” Kirill said. “Ours was a significant peacemaking dialogue.”

The phone exchange came after Kirill and Francis had broken the ice in 2016 with a meeting in the Havana airport as the pontiff was en route to Mexico, ending with a joint declaration expressing, among other points, shared concern for the persecution of Christians in the Middle East and the violence scarring the region.

Though Vatican officials stressed that the idea for Francis’s ecumenical summit in Bari pre-dated the April phone call from Kirill, that conversation obviously lent momentum to the gathering and created lively expectations that the Russian Orthodox leader might attend. When the event was officially announced in Rome on April 25, Vatican spokesman Greg Burke didn’t rule out the possibility.

To be sure, there are several fairly clear reasons why Kirill may have felt that showing up in Bari would have been a bridge too far.

For one thing, Moscow’s relationships with some of the other Orthodox churches of the world aren’t always the best. That’s the reason the Russian Orthodox didn’t participate, for instance, in the “Holy and Great Council of the Orthodox Church,” a pan-Orthodox summit hosted in Crete by Patriarch Bartholomew of Constantinople in June 2016.

The Russians cited specific objections to the composition of the council in explaining its decision, including the fact that representatives of the Antiochian, Bulgarian and Georgian churches weren’t in attendance. Beneath all that, however, is the fact that Constantinople and Moscow are natural rivals for preeminence in Orthodoxy – the Patriarch of Constantinople traditionally is the “first among equals,” but Moscow has both the numbers and the resources to be the real 800-pound gorilla.

Right now, Moscow and Constantinople are wrangling over a possible move by the latter to recognize the independence of the Orthodox church in Ukraine, something Hilarion recently warned would “mean a schism, similar to the schism of 1054.”

In addition, several theological disputes still loom large in the relationship between Moscow and Rome. Hilarion reminded the world of one of those disputes, over the procession of the Holy Spirit, in a late April interview with Russian TV. Asked about comments by Bartholomew that reunion between Catholicism and Orthodoxy is “inevitable” at some future point, Hilarion expressed strong skepticism.

Many Russian Orthodox, including a strong cross-section of the church’s politically influential monks are leery of the entire ecumenical enterprise, seeing it as an invitation to paper over differences and water down the church’s distinct identity.

Most basically, perhaps, Moscow has long feared that “reunion” with Rome would actually mean absorption, meaning an imbalanced relationship in which the pope would always be the senior partner and would therefore set the terms.

Thus, an invitation from the pontiff to take part in a high-profile summit on Catholic turf – even if Bari contains the relics of St. Nicholas, making it a popular pilgrimage site for Russian Orthodox believers too – likely triggered one of the Russians’ deepest historical anxieties about where all this is heading.

While those points may contribute to an explanation, they don’t address whether skipping Bari was ultimately a wise move for Kirill. From a realpolitik point of view, one could argue that he would have increased his leverage both with Rome and the rest of the Orthodox world by showing up; in terms of more idealistic considerations, one could also suggest that petty doctrinal differences should yield to the pressing cause of a united Christian witness in favor of Middle East peace.

It should be said, by the way, that Kirill’s non-attendance doesn’t mean that Catholics and the Russian Orthodox can’t come together for the Middle East; in fact, the TASS news agency recently reported that the two sides will collaborate on rebuilding churches in Syria destroyed by ISIS.

Yet it’s not difficult to imagine some skeptics wondering, if the heads of the Catholic and Russian Orthodox churches can’t even be in the same room to pray for the Middle East, whether there’s much point in any ecumenical endeavors.

In any event, Kirill may well feel he doesn’t have a great deal to lose by allowing his chair to have remained empty. “Silent Cal,” after all, went on to win that 1924 election in a landslide, while Wheeler and his Progressives captured exactly one state (Wisconsin, home of their presidential nominee Robert Lafollette.)

Not showing up, in other words, sometimes may be smart politics. What remains to be seen is if it’ll yield the same results for Kirill it did for Coolidge.