My Mum had a saying. Actually, she had lots of sayings, but one of them has always been a particular favourite: “Don’t only see the holes in the Emmental”.

I’ve been sharing them with audiences at book festivals all over the country, talking about the history of my family. I don’t think its ever been more important.

In 1919 my grandfather Alfred Wiener returned to Berlin from the Front and wrote a tract that was among the earliest warnings of what was to come in Germany. He talked of the rise of conspiracy theories and rumours about Jews, of the growth of violent gangs, of the way this antisemitic agitation was financed, and he said that if Germans did nothing, history would “report bestial murders and violence to our descendants.”

I first read this as I worked on Hitler, Stalin, Mum and Dad, with my son Sam, who did much copy editing on the book. And we reflected that our work meant that history was indeed reporting bestial murder to Alfred’s descendants.

It was hard not to reflect upon the warnings Alfred was making, and wonder about the parallels with the current moment in Britain. I think most of us would acknowledge an unease that we didn’t have ten years ago. The conspiracy theories Alfred wrote about are on the rise here, there are more incidents of violence and antisemitic abuse, there seems to be more money and organisation behind them.

So I have told my book audiences that the lesson from Alfred’s tract and the subsequent history is that we must be alert. We must be on our guard. We mustn’t stay silent. We need ourselves to be organised and to build our alliances.

But I have told them something else. That already by 1919 Alfred was telling of a situation far worse for Jews than our experience now. All the problems he warned of were far more advanced. So yes, we must be alert, and yes, we must be on our guard, but we must also show a sense of proportion. A sense of proportion is not complacency.

Part of the reason for insisting upon this is that I don’t wish to live in fear, especially when I don’t need to. I don’t want to feel as though I am not safe in my own city when truly I am. I don’t wish to feel as if London is a no go area every weekend when it is not.

I am distressed and angry that antisemitic banners are waved in central London on weekend after weekend. I am outraged at the fact that removing magen davids is a sensible precaution that many have felt they had to take. I do not minimise this or how upsetting it is. I am appalled. And I worry about trends on social media and among young people.

But I don’t want to be cowed by it. This is still a wonderful country for Jews to live in. The institutions of this country — parliament, the courts and, yes most certainly, the police — protect our freedom and our security in an impressive way. Overwhelmingly we live here in peace, able to practice our religion as Jews and still be fully British.

When Labour briefly showed its willingness to allow virulent anti-Zionists to advance conspiracy theories about Jews from within its ranks, voters withheld their support. The leadership was toppled and was replaced by a new leader determined to tackle the problem.

I know there are some people who say openly that they now see no future for us here. Certainly not for their children. And I hear this, of course I do, but I can’t agree.

The challenges Jews face all over the world are great. And if we are going to face them we need our wits about us. We need to keep calm. And we need a sense of proportion.

Unfortunately at all stages of our history and all over the world Jews have faced threats and suffered because of the hatred of others. But I think that modern Britain is one of the best places for Jews to live that there has ever been. Even now. I don’t just mean that in a loose rhetorical way. I think it is a factual statement.

Hitler, Stalin, Mum and Dad will be published in paperback by William Collins on June 6th 2024 (£10.99)