How Belfast knife attack became the latest far-right ‘trigger event’

The rapid spread of footage shows how social media is pivotal in enabling far-right agitators to mobilise internationally

Filmed at about 10.30pm on Monday night on a Belfast street, bystanders captured the moment when a man, believed to be a Sudanese asylum seeker, wielded a knife over another man he had pinned to the ground.

By Tuesday, the clip had become the latest transnational “trigger event” – in the mould of the Southport killings and the case of the murdered 18-year-old student Henry Nowak – as far-right activists from Britain and beyond seized on it.