After Hitler, humanity would surely see where the world’s most insane hatred led and resolve to put it to one side.
Bertolt Brecht said: “Do not rejoice in his defeat, you men. For though the world has stood up and stopped the bastard, the bitch that bore him is in heat again.”
Describe the fantasy the Tsarist and Nazi empires developed that bluntly and it is impossible to understand how the Labour party is in danger of becoming as tainted as Ukip by the racists it attracts.
But consider how many leftwing activists, institutions or academics would agree with a politer version.
Western governments are the main source of the ills of the world. The “Israel lobby” controls western foreign policy. Israel itself is the “root cause” of all the terrors of the Middle East, from the Iraq war to Islamic State. Polite racism turns the Jews, once again, into demons with the supernatural power to manipulate and destroy nations. Or as the Swedish foreign minister, Margot Wallström, who sees herself as a feminist rather than a racial conspiracist, explained recently, Islamist attacks in Paris were the fault of Israeli occupiers in the West Bank.
Or consider the otherwise bizarre indulgence of ultra-right religious extremists by people who otherwise describe themselves as liberals and leftists. The belief that Jews fuel radical Islam allows them to overlook superstition and the tyrannical denial of equal rights. They’re against Israeland that’s all that matters.
We will learn the essential lesson that antisemitism is not about Jews, but power