In my experience bullying and persecution are very often more about fear and insecurity. If you're persecuting and blaming someone else, you're not being persecuted and blamed yourself. It's a way to deflect hostility and responsibility away from yourself and on to other people. It seems to me most of the people Russel was writing about may not even have been going along with the mainstream because they genuinely thought Jews, Communists etc were a real threat, but because if everyone is having a go at them they're not having a go at me. If I join in then I become one of the team and can buy safety and security for myself that way. In the uncertain and dangerous times Germany had been through, any route to personal security and safety must have looked very attractive.
How is this relevant today? Clearly Putin is using this sort of response to great effect by using conflict and rivalry with foreigners to deflect criticism away from his abysmal record at actually achieving anything of value for the Russian people. Even having a Russian jet shot down by Turkey plays to his advantage in that respect.
For us the question is, how to treat Muslim minorities in the West, and what to do about the Syrian refugee crisis. The refugees didn't create this crisis and are the primary victims. The vast majority of Muslims in the west are against ISIS and deplore it's tactics. But blaming 'The Muslims' for all of this and using excuses such as that terrorists will infiltrate the west disguised as refugees are blinkered and cowardly. What are we going to do? Drive millions of refugees back into the Mediterranean sea?
It's going to take determination and perseverance to do the right thing. Take as many refugees as we can. Build bridges with Muslim communities in the West. Confront IS and it's backers militarily and economically. There will be further attacks. Integrating so many refugees is going to be expensive, hard work and there are going to be negative consequences and mistakes made. It's not going o go smoothly. But we still have to do it not because we are 'Intelligent' but because we have courage.