> Terrorism as performance art, successfully gaining the sympathies of the population (provided it isn't too extreme) and driving the government to give the terrorists what they want?
While the term 'terrorist' seems a bit connoted to me, there is indeed a sort of bargain/blackmail dynamic in most protests and funnily the french population routinely describes itself 'hostage' when the situation leads to disturbance of public services or infrastructures.
> This is the kind of thing I'd expect in Yemen or Somalia, not western Europe.
Right, peaceful protesting in countries at war is probably not too frequent. Although in the case of Somalia, protests must be kind of interesting since there is essentially no government.
>I suspect in the UK or Netherlands (places I'm more familiar with) attitudes would be a lot closer to US.
Absolutely, for tons of cultural and social reasons. Although I observe that all the countries you listed did at times have violent rioting as well.