Any pope who travels from Havana to the United States on a mission to persuade Congress to uplift the poor and address global warming has to be pretty audacious. So on his coming trip, Pope Francis will no doubt spark speculation about his potential for diplomatic miracles.

The Vatican is no stranger, of course, to high-level diplomacy or dialogue with communist leaders, although dealing with the current crop of U.S. legislators may be tougher. Yet it is especially fascinating to watch Pope Francis’ energetic efforts to address international crises ranging from refugee flows to violence in the Mideast and Ukraine to global inequality.

Although his diplomatic forays have had mixed results, he has become a powerful symbol of the worldwide thirst for social justice, focusing on the peripheries of the world in Asia, Africa, Latin America and the Mideast. This has made many world leaders, including President Obama, Russia’s Vladimir Putin and China’s Xi Jinping, pay attention. Perhaps they recognize that, more than most prominent secular politicians, Francis grasps the temper of our times.

In an era when people worldwide have soured on government institutions and corruption, Francis has rejected Vatican splendor for a simple personal life and moved to clean house after years of priestly scandal. His first trip outside the Vatican was to the island of Lampedusa, the part of Italy closest to North Africa, to place a wreath on a memorial to migrants who died trying to cross the Mediterranean.

In a globalized world where people hunger for connection, he eschews bureaucracy and reaches out directly to worshipers, even washing the feet of the disabled and youths in juvenile deten-

tion. At a time when evangelical churches, with their emotional brand of religion, are expanding exponentially, Francis’ charisma and passionate appeal for social justice have made him a religious rock star.

The big question is how effectively he can apply his accumulated soft power to make a difference on the world stage.

So far, the record is mixed. His godfathering of U.S.-Cuban reconciliation was stunningly successful, but his Mideast efforts much less so. After visiting Israel and the West Bank last year, he invited the Palestinian and Israeli presidents to Rome to pray together at the Vatican, but the August 2014 Gaza war exploded days later. He opposed Western military strikes against Syria in 2013 and has met twice with Putin to discuss ending the wars there and in Ukraine, but the violence in both places continues.

Yet the pope’s call this month for every Catholic parish in Europe to take in refugees, as their numbers in Europe reached record levels, resonated powerfully, especially given that nearly all are Muslims.

At a time when the extreme Muslim fundamentalists of ISIS are promoting a theology that calls for the eradication of Christian and other minority communities, Francis is presenting the world with a wholly different theology that stresses inclusion and tolerance. It should be a model for all faiths.

But the pope’s most audacious foreign-policy move has been a crusade against worldwide income inequality and environmental degradation, including man-made climate change. Conservatives may decry his critique of capitalism or his stern warnings about global warming; environmentalists will dispute his rejection of carbon-trading as a solution. But the moral force of this pope and his message could provoke a more serious debate on issues that politicians prefer to fudge, deny or ignore.

We don’t know yet whether Francis’ approach can mobilize enough grassroots pressure to move political elites. But at a minimum, U.S. legislators — and world leaders at the U.N. General Assembly — will have to pay attention to a pope who will continue to inject his concern for the poor and the environment into international discourse.

Any world leaders who decide to act can cite the pope as cover. They can also use the Vatican as an intermediary in sensitive talks or as a secret locale for dialogue, as Obama did with the Cubans.

Pope Francis has clearly positioned himself to play such a role and to act as a tireless emissary for the disenfranchised. His determination will be evident in Washington and New York this week.

Trudy Rubin is a columnist with the Philadelphia Inquirer.