In an article in a British Sunday newspaper (The Observer 26 January), former Prime Minister Tony Blair identifies conflicts fuelled by religious extremism as the Big Issue for the 21st century.
It's true that the willingness of some young men around the world to resort to terminal violence as their first line of response to things they dislike is scary, but if you can get past that gut feeling and fear, it seems that there is nothing new about the intensity of their hate or its typical focus.
People have always reserved their greatest hatred for those who are physically close but culturally different. Often enough, the hatred boils up or is channelled into lethal attacks to drive out or exterminate those who are different.
The rational basis or rationalisation is often enough that the Other will monopolise scarce resources - land, food, employment - or exploit those who perceive themselves threatened.
Over the centuries, European Jews whose involvement in commerce brought them physically close to populations who differed from them were subject to repeated pogroms which even, in at least one instance in Poland, continued after the second world war.
You would have thought that in America or Australia, there was enough land for everyone, but European settlers there could not tolerate the idea of sharing or living side by side with Red Indians or Aborigines and so exterminated them. (A manifestation of European civilisation which Hitler found inspirational for his own schemes).
It was almost inevitable that when the state of Israel was founded, the Zionists would drive the Arab population from their ancestral lands - a process which continues to this day. (Ironically, many of those Arabs have a better claim to be in the blood line of the Chosen People than the very mixed race European settlers who have driven them out).
In England, there has never really been organised violence against the Other but always a level of hostility which sometimes breaks out into low-level intimidation and unpleasantness. In the 19th century, Irish labourers were the hated Other; after World War Two, West Indian bus conductors and railway porters; this week, it is Bulgarians and Romanians. Resentment is articulated in claims that They take Our jobs and homes, though it is never explained why we are so bad at holding onto our jobs and homes when we have all the advantages of language and familiarity with the system.
There are other kinds of proximity-based hatred. Put orphans into close proximity with Catholic nuns and they don't stand a chance. Put delinquent boys into close proximity with Catholic monks and you get institutions where everyday life is a system of generalised abuse and violence.
Last but by no means least, there is the hatred of the Other sex which can reach the same kind of murderous intensity as other hatreds. In some places, women go about their lives on edge, as if at any moment a pogrom may break out around them and directed at them with acid attacks, rape and murder as the weapons
Anyone who suggests that it's a better idea to love your neighbour is taking on a tough assignment. Historically, the evidence is that it may well prove terminal.
Tony Blair doesn't urge us to love our neighbours, simply to tolerate them. History suggests that is not something which comes easily, and certainly not to his American friends. They can barely tolerate Cuba.