ROME — Pope Francis said that policies proposed by populist politicians to curb mass migration only serve to stoke hatred and fuel fear, comparing them to Nazi rhetoric on Sunday.

In an address to a gathering organized by the Italian bishops’ conference in the southern Italian city of Bari, the pope connected dots between war, international migration, and climate change, three key issues of his pontificate.

Francis underscored the plight of “all who are fleeing war or who have left their homelands in search of a humanly dignified life,” while urging European nations not to close their borders to them.

“The number of these brothers and sisters – forced to abandon their loved ones and their lands, and to face conditions of extreme insecurity – has risen as a result of spreading conflicts and increasingly dramatic environmental and climatic conditions,” he said.

“While countries experiencing this flow of migrants and countries to which they travel are affected by this, so too are the governments and Churches of the migrants’ countries of origin, which, with the departure of so many young people, witness the impoverishment of their own future,” he added.

In this context, the pope had harsh words for populist politicians such as Italy’s Matteo Salvini who have characterized recent mass migration into Europe as an “invasion.”

“Fear is leading to a sense that we need to defend ourselves against what is depicted in demagogic terms as an invasion,” Francis said. “The rhetoric of the clash of civilizations merely serves to justify violence and to nurture hatred.”

The pontiff said it is “unthinkable” to try to address the problem of immigration by erecting walls.

“I grow fearful when I hear certain speeches by some leaders of the new forms of populism; it reminds me of speeches that disseminated fear and hatred back in the thirties of the last century,” he said, in reference to the rise of Fascism and National Socialism.

The Mediterranean “is the sea of intermingling,” Francis said. “Notions of racial purity have no future.”

“The message of intermingling has much to tell us,” he said. “To be part of the Mediterranean region is a source extraordinary potential: may we not allow a spirit of nationalism to spread the opposite view, namely, that those states less accessible and geographically more isolated should be privileged.”

“As I said, it is unthinkable that this process of acceptance and dignified integration can be accomplished by building walls,” he continued. “When we do so, we cut ourselves off from the richness brought by others, which always represents an opportunity for growth.”

Efforts to resist international migration “stand in the way of the unification of the human family, which despite many challenges, continues to advance,” he said.

The pope also referenced recent comparisons of biblical figures and Jesus himself to migrants and refugees.

“Last week, an artist from Turin sent me a little wood-burned picture of the flight to Egypt with Saint Joseph, not the peaceful Saint Joseph we are used to seeing on holy cards, but Saint Joseph in the guise of a Syrian refugee bearing a child on his shoulders,” Francis said. “It portrayed the pain and the bitter tragedy of the Child Jesus on the flight to Egypt. The same thing that is happening today.”

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