Sadly, stabbings are not infrequent in London - especially in areas referred to a 'disadvantaged deprived, excluded', etc - but more often than not these occur within 'communities' who prefer to settle their own local disputes and avoid involving the police. If there was a large-scale out-break of such knifings between, say, BNP, Muslim, Sikh, Carib or other concentrated groupings - then our Riot Squad police would have to intervene - with their shields and baton sticks. Backed-up with tasers and water-cannons, if necessary.
Fortunately, we wouldn't expect our armed police to turn up shooting at massed crowds - as often happens elsewhere. If things got out of control 'all over London' (as you surmise) - our Prime Minister would declare 'A State of Emergency' and call in Her Majesty's troops - to quieten things down. (We have more than a few Regiments of HM's Guards and Cavalry troops stationed in London - to cope with any such emergencies ; )) Hopefully - with few being SHOT with lead bullets.
My cousin is a bobby in London. I visited the city 8 years ago and it had so changed into a ghetto that we all we surprised.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.