"We cannot let ourselves be blinded by people who seek to drag us into a spiral of violence."
No. You cannot let yourselves be blinded by your own denial, i.e. your own refusal to face reality.
"We Dutch are easy prey."
Note the inferences of "victimhood" and self-congratulation.
"We're vulnerable because we're a soft, tolerant society."
No, you're vulnerable because you refuse to face reality.
Any good thing taken sufficiently to its extreme becomes a bad thing. This is the ancient Greek concept of nemesis. Tolerance is no exception.
Furthermore, being realistic about the limits of tolerance does not mean that you must abandon tolerance.
Thank you, I have been looking for a good line to apply to various things, in this case tolerance, but can be applied equally well to immigration, and diversity. Well spoken, (and the etimology is nemesis, very interesting)