Frankly I think you've already pointed out why these type of attacks are occuring - lack of integration. Or what I think can be called marginalisation.

Overall politicians have taken the view that the country as whole becomes stronger if it includes lots of different backgrounds. That many people live in very marginalisaed communities is a problem for everyone as it creates the conditions under which people become desperate and isolated and hence more susceptible to extremist viewpoints because it provides them with a sense of purpose that they lacked.

So, more youth clubs, police on the beat, and social policies to reduce this marginalisation reduce the likelihood of these conditions occuring. You need all those resources to stop emergent troublemakers and respond to those who are actively engaged in these atrocities at whatever stage too, of course.

But the left has always been better at understanding social marginalisation than the Conservatives, who seem pretty clueless to me. Rounding 'em up only works if you have a way of charging them with something, or otherwise, as Stirling pointed out, you'll just increase the likelihood of the other lot feeling even more isolated and ready commit this kind of horror.

Just to lighten the mood a bit,on that subject in my bar in Spain, I used to have a barmaid (Irish but that's not it).
We were watching the news one day and there was a suicide bombing in an middle eastern country,can't remember where,....and her actual words were "I hope that catch the b******s".

always a Norwood boy, where ever I live.

Same old Labour. Full of s**t.

"Look at that. Accident blackspot? These aren't accidents! They're throwing themselves into the road gladly! Throwing themselves into the road to escape all this hideousness!"

Didn't think you were a fan of whataboutery?

In answer to your questionthough, the various specialist firearms officers (I think the Met call them CTSFO) that are stationed around the city would deploy to the nearest incident. They would be supported by "normal" armed police and also of course, unarmed police.

We suspect that they don't conform to our way of life so let's go round their house and kill them.

That idea sounds remarkably familiar to how Daesh operate.

Would the army be involved? Are their different rules of engagement