American nationalists’ European vacation

LONDON — America’s far-right online activists have found a playground abroad.

Since the election of President Donald Trump in 2016, right-wing digital groups and online activists who helped get him elected have exported their divisive playbook to Europe through digital chatrooms, encrypted messaging apps and the occasional trip across the Atlantic.

Their goal: to road test tactics for the 2020 U.S. presidential race in the Old World.

Over the past three years, American...