No-one has banned hijabs because they pose a security threat. Hijabs don't obscure the face.

Well, there's France and its recent decisions against the "burkini" and similar clothing, but it was widely mocked and as far as I know, at least one court has already overturned the ban.

> but it was widely mocked

It's also been enforced by police who've forced women to remove clothing: https://www.theguardian.com/world/2016/aug/24/french-police-...

There's been other violence against women for what they wear:

>> A Corsican mayor has also banned burkinis, amid tensions on the island and violent clashes between villagers and three Muslim families. Skirmishes at a beach in the commune of Sisco earlier this month left four people injured and resulted in riot police being brought in to stop a crowd of 200 Corsicans marching into a housing estate with a high population of people of North African origin, shouting “this is our home”.

(etc, there are many attacks on women who wear hijabs or niqabs)

Fair enough, I didn't mean to imply there's no discrimination against women wearing those and similar clothing, just that "state-enforced laws" against them are thankfully still not widespread across Europe, though I fear they might be in the future.

> There's been other violence against women for what they wear.

Is that example entirely a result of the clothing, or are there other factors at play? i.e. is causality established.