Yet, in terms of actual behaviour, JWs do not advocate or carry out any part of this 'destruction'. Is that an extremist belief though? Yes. Does it lead to extremist behaviour? No.
That's the major difference between Christians and Muslims. Whatever the Christian belief about non-believers and what's going to happen to them, they usually believe that God is the one who's going to do any smiting. Yes, it's sick that they think they get to watch, but it's passive. They can wait for their imaginary friend for another 2,000 years and not do any harm.
But Muslims believe that they must act out Allah's vengeance on the infidels themselves in order to get his blessing which makes them vastly more likely to be dangerous and extreme from the get-go.
A christian practicing their beliefs is usually a normal, functioning member of society. A muslim actually practicing their religions beliefs is a psychotic killer.
Although I am not convinced that the Muslims living in my local community could be described as extremist in terms of their behaviour on the basis of the above argument.
A genuine muslim is not your friend - they cannot be both, their religion doesn't allow it so one of those is a lie. But thank god most of them are frauds and hypocrites who are only in it to survive the culture that imposes it on them.