If you want to strike your enemy, you always search for the weakest point, the softest or easiest target. You look for holes in the enemy’s defences, and take advantage of them. If the enemy’s borders are porous, that makes it easy. If there is a fence, you find a hole in it or a weak spot from which to launch your attack.

Those are examples of the physical aspects of an attack. But those who fight wars using terrorism are about far more than inflicting physical death or destruction.

They search for soft targets, like any enemy, but the barriers are not just fences, they are hearts and minds. And what is the softest target of all? The target that doesn’t realize they are a target, let alone why they are a target. The target that even after attacked, keeps asking the most bizarre questions like: “Why would they want to do this to us?” or dismisses their enemy as “insane” and then invert the attacker-victim dynamic by asking: “What did we do to make them want to attack us?” They are the softest targets of all because they don’t recognize a war even when they are in one.

Israel is generally not a soft target, because Israel knows an enemy when they see one. After all, they are surrounded by them, so they are easy to spot. They know that their enemies seek their destruction — “Palestine from the river to the sea” — not any silly compromises like a two-state solution and two nations living side by side in peace. Those are slogans said publicly in English by Palestinian leaders to the world (but never in Arabic to their own) that continue to allow billions to fill the coffers of a kleptocracy.

There are some in Israel who still hold a candle for some magical peace that will come if we make just one more concession and give away still more land, and look for blame everywhere except with the perpetrators and inciters of violence. They too are soft targets.

Why Paris? I don’t know if Paris as a city symbolises liberty and the Western way of life any more or less than the World Trade Centre did, or Charlie Hebdo did. More importantly, I don’t know if ISIS (or Al Qaeda) are into symbolic gestures. But they definitely know a soft target when they see one, and they strike at them hard.

They know that hitting a soft target will cause confusion, self-doubt, internal recriminations, just as we have seen time and again. A soft target crumbles emotionally when struck, no matter how many people on social media change their profile pictures or tweet hashtags of support. A soft target continues to live in denial.

A hard target stands firm and resolute, because they know they are fighting a war. It may not be a war of their choice, but it is a war nevertheless. They know that a war of this kind must be fought with real weapons to be won, not with diplomacy, because you cannot negotiate with a terrorist. They know that being swept up in a war hurts, and will take its toll on their own – both physically and emotionally. But because they know it’s a war, and they know their continued existence and way of life depends on winning that war, they develop a resilience that helps them weather the storm.

I think ISIS looks at Europe as a soft target. The question is: will Europe realize that this really is war?