By Patrick Smith, NBC News

LONDON — The racist attack in Buffalo, New York, is part of a broader movement that experts and officials fear could inspire further white nationalist terror across the world.

Though the suspect alone allegedly drove 200 miles from his hometown to carry out the massacre, his apparent online footprint suggests he formed part of an informal global network of radicalized young men inspired by racist conspiracy theories and far-right attacks from Norway to New Zealand.

London Mayor Sadiq Khan said this week that the Buffalo shooting “highlights the growing threat of far-right extremism in the U.S. and Europe.” Cities and nations need to unite against this “evolving global danger,” he said.