Yeah, not good.

PARIS (AFP) – The thwarted attack by a gunman on a high-speed train between Amsterdam and Paris has underlined the difficulty faced by intelligence services in tracking the unprecedented numbers of potential Islamic militants, experts say.

The Moroccan suspect in Friday’s incident, identified as 25-year-old Ayoub El Khazzani, was first flagged by Spanish authorities as a potential extremist and had reportedly travelled to Syria.

He was overpowered by two US servicemen and other passengers before he could kill anyone in the train.

In a timely interview published on the same day as the attack, Alain Grignard, a senior member of Belgium’s counter-terrorism police unit, said the terrorist threat has “never been higher in all the years I’ve been working”.

“It boils down to mathematics and it’s all linked to the Syria dynamic,” Grignard told CTC Sentinel, the in-house journal of the US military academy at West Point.

“There’s no way of knowing the exact numbers but I can tell you with certainty that at least 300 have travelled – that’s the number we have sufficient evidence to bring charges against. At least 100 have returned to Belgium, but we are under no illusions that there aren’t more we don’t know about. It’s impossible to do surveillance on everybody.”