Ian Bremmer, author of "Every Nation for Itself" and "Superpower," now takes on the populist backlash against globalism with a stark warning about where this trend might be headed in his new book, "Us vs. Them: The Failure of Globalism," out April 24.

Ian's insight: It’s not just Europe and America. Technological and economic changes, the historic flow of people across borders, and public demand for protection have empowered a whole new class of politicians with a talent for pitting one group against another.

• The scale: The book goes deep on a dozen countries, including China, India, Russia, Brazil, Turkey and others.
• A warning: Walls, real and virtual, are on the rise. Think repression + populism + protectionism for the digital age.

There’s a hopeful vision, too:

• To adapt and survive, some governments will experiment with ambitious plans to rewrite the social contract that underpins society. 
• They’ll remake the way children and adults are educated, how workers can be retrained, and how societies can prevent a widening of the gap between rich and poor.

Go deeper ... Read an excerpt ... Here’s some video of Ian sounding the alarm.