Canada’s counter-terror efforts face scrutiny after US helps stop suspect

Troubled by his posts online that praised Isis and his correspondence with militants plotting attacks around the world, Canadian officials began watching Aaron Driver in 2014.

They soon went one step further, imposing a strict set of restrictions including reporting regularly to police and staying off social media.

But when Driver, 24, released a video in which he pledged allegiance to Isis and warned of an imminent attack on a Canadian city, it was US officials who alerted Canada.