The nationalism that’s sweeping the globe is among the biggest risks facing developed nations, Blackstone Group LP’s Stephen Schwarzman said.

The “geopolitical is what worries me,” Schwarzman, chief executive officer of Blackstone, said in a meeting with investors and analysts Friday in New York.

Many countries are “breaking to either the right or the left. There used to be a center,” he said. “The concept of the center is being tested.”

Schwarzman also said the global economy is “quite good, led by the U.S.” He cited the U.S. move toward deregulation, tax reform and record low unemployment.

It’s “easy to have a positive conclusion” about the global economy, but “some geopolitical stuff hasn’t been reflected in the numbers.”

This article was provided by Bloomberg News.