From my understanding of modern Islam, I don't find anything that
Thomsy has put forward on this thread remotely surprising. In fact, I think it's pretty much on the money. Although I would not pretend to be an expert, it is entirely in line with stuff that I have studied at university and subsequently and friends who know much more than me who I have spoken to about things like this.
However, that does not necessarily mean that the NYE attacks were a reflection of a religious sensibility alone or even principally. That may have been, indirectly, part of the multifarious influences that came into play but my impression is that there were many other, perhaps more concerning, aspects at play - fundamental respect for women's rights, attitudes to the sexualisation of western women in particular, the rapid development of a rape culture amongst young men, and all within a fairly specific group of immigrants from a small range of related ethnicities and backgrounds; perhaps more than anything else reflecting the cultures that they have grown up in, and here is where you can loop in Islamic essentialism if you like and you probably would not be 100% wrong, but it is only part of a much bigger picture from my point of view.
Nonetheless, leaving the details of causality and motivation aside, it's pretty clear that this is a real issue that must be addressed and the apologists who point to Western foreign policy or who attempt to explain that integration on Western cultural terms either (i) will happen because these are fundamentally good blokes who have merely had a rough time of things recently or (ii) that integration is not really necessary at all and everything will quieten down in a stable multicultural peace are deluded.