Understanding the effects that terrorism has on society is an essential pre-requisite to deciding how to stop terrorism.
As vitally important as this is, understanding does not come easily.
Many people in almost every society on earth simply don't understand. They neither understand what it does to their own society, nor what it does to the society of the people who perpetrate the acts of terror.
Terrorism is a corrosive and deeply painful phenomenon on both sides. But this does not mean the two sides are the same or similar or even comparable.
Since their faces and ages are almost completely unpublished anywhere in the world, here below are the eight murdered victims of the well-planned, cold-blooded massacre of students in a Yeshiva library that took place on Thursday night. Still others are fighting for their lives today in Jerusalem hospitals.
Now for a look at what goes on inside a society whose moral tone, whose educational and social values are interwined with a religious love of death and an embrace of hatred:
Palestinian-Arabs dancing in Gaza.
Palestinian-Arabs dancing in southern Lebanon
Celebrating the massacre - Jabaliya, Gaza
As parents of a child murdered in an earlier massacre of children, we're frequently advised to look to "root causes" for an explanation of how the Palestinian Arabs - uniquely in the world, uniquely in history - have created a society whose most basic values are rooted in terrorism, whose very name is a by-word for terrorism.
"Root causes", as we have noticed again and again in the rhetoric of Palestinian terror's apologists, is a synonym for occupation. The shallowness and historical wrongness of that diagnosis is clear to anyone who knows how many villages and acres were "occupied" when Arafat took the reins at the PLO in 1964. (Hint: zero.)
There's only one root cause; it's hatred. It's immensely difficult to teach understanding and tolerance. It's far easier to teach hatred, and giving it a religious underpinning makes it easier still, and more potent.
When the world, and in particular Palestinian Arab society, understands the role that their home-grown hatred has in the evolution of men, women and children ready to blow themselves up just so long as they can take the lives of their Jewish enemy, we will have taken the first and by far most important step towards changing this appalling situation and ending this ongoing war.