By George Friedman

Summary The attacks in Belgium will set in motion an old cycle: massive alerts, terrorists going to ground, relaxing the alert, the re-emergence of the terrorist. Identifying terrorists consistently is almost impossible by existing means. The only strategy that might work is human intelligence – spies penetrating terrorist groups – but it is stunningly difficult. The choice is living with terrorism or adopting new strategies, as the old ones stop some attacks but not all.

Another terrorist attack took place in Western Europe yesterday. Security will now be on alert around the world. The terrorists will avoid attacks during this time because the danger of interception and failure are too high. Therefore, there will be no more terror attacks in the coming days, although there will be constant alerts about empty boxes and suspicious people. In due course, the special alert will not end as much as fade away. Terrorists will begin planning for new attacks and as the events of today blur in our memory, a new attack will take place and the cycle of terrorism and counterterrorism will turn its crank once more.

Being constantly on full alert is impossible. A single human being on highest alert on a permanent basis will either self-destruct from adrenaline exhaustion or will decline into a haze. The same can be said for a police or security force. Its ability to endure a constant crisis posture is as limited as for a single person – because the force consists of people. That is what drives this cycle. The surge of adrenaline following an attack is natural. It also takes place at a time when a new attack is most unlikely. Surging the force later, when it has been months since the last attack and the threat is distant, is extremely difficult. You can’t order up the adrenaline – individual or collective – required to go on full alert. The threat must be real, and the terrorist organization understands this, so it works hard to take advantage of the human tendency to regard the rare as an illusion.

Any successful counter to terrorism can’t be carried out by security forces. It must be carried out by intelligence services. Security services respond and create a presence that must be evaded. Intelligence services probe into the intentions of the enemy. Their job is to identify those who wish to carry out terror attacks, trace their network and leave it to the police and security forces to capture them.

The intelligence problem is simple. How do you discern intention? Most intelligence focuses on capabilities, but the capabilities required by a terrorist are readily available and transportable. You cannot track capabilities because virtually anyone could be capable of the attack. The Middle East is awash with explosives. Traffic – legal, illegal and refugees – moves in masses from the Middle East to Turkey and then to Europe. Similarly, explosives are readily available in the former Soviet Union, especially in places like Chechnya. Intercepting the explosives needed for a suicide bomb is possible, but the flow is so massive that all of the explosives flowing cannot be interdicted. And some of the explosives can be made in Europe, from fairly common material by those who know how to do it. And such people are readily available and can’t be identified as bomb-makers just by looking at them.

The intelligence challenge is to identify those with the intent to carry out terror attacks and ability to access the material. Identifying both is critical. The world is filled with loudmouths announcing coming heroic events who have neither the access nor the knowledge to carry them out. The security forces have limited capacity. If they went after everyone claiming to be the Jihad King, their resources would be exhausted. In fact, terrorists would encourage all of their followers to publicly declare their intent to blow up something. That would leave an opening for actual terrorists. Alternatively, if you went after everyone with plastic explosives, you would be chasing shadows. How do you know if they have access to an explosive like C-4? The usual solution is to get an unbelievably expensive piece of portable hardware that will sniff out C-4, which will be available in four years, and produce as many false positives as false negatives. Technology is useful, but relying on it is hard. And taking it to the right place to sniff – well you are back to intelligence.

And the problem of intelligence is that it must assume that anyone might be a terrorist. Intelligence of this sort is a process of discarding. You begin with the assumption that you have no idea what you are looking for, and over time you find the basis for dismissing some, then more and then focusing on a few. This sounds reasonable, until you consider that the process requires you to examine virtually everyone. If everyone is suspect – and they should be – then everyone is subject to examination and no one has the right to privacy.

The problem is that terrorism, by its nature, gives out limited signals. It can be carried out by very few people. It requires limited resources. It requires little money. It requires limited communication. Unlike organized crime, which involves money laundering, the delivery of massive amounts of interesting smelling products or the ownership of fleets of vehicles – all of which might point you to the right place – terrorism has a much lighter footprint. There are no fleets of cars or massive movements of products and limited money.

So how do you find the terrorists? To the extent they can be found, it requires a massive intrusion into society. Since there is no exchange of millions of dollars, you must inspect transactions of $500. Since there is no massive flow of product, you must subject all cars to inspection.

Obviously, there is one common denominator in this group of terrorists. They are Muslims and for the most part – but not exclusively – from a region ranging from North Africa to the Middle East to Afghanistan. That is a common denominator but actually not a very useful one. Assuming that most terrorists are part of this group, they are an infinitesimal part. I say this not because it is politically correct but because it is true. If they were more numerous they would be easier to catch. One of the strategies of terrorism is to keep the number of terrorists extremely small. If they expand and communicate with others, they will be detected. So given the number of Muslims in Europe, the exclusion of Swedish grandmothers from the profile you are looking for still leaves a number that dwarfs police security intelligence and the army as well. Racial profiling doesn’t work because terrorists aren’t stupid.

So what would work given the resources available? The most important measure would be the penetration of the command structure of terrorist organizations with spies. Some would sneer at this, saying it is old fashioned and that technical means of intelligence from satellites to telephone intercepts are superior. The problem with this is that the terrorists are well aware of government capabilities. They understand the value of not speaking on the phone and conducting conversations by writing instead. And they knew this long before Edward Snowden revealed what those interested already knew.

Human intelligence is required at all levels of terrorist operations, to win the trust of the members, carry out terrorist (but not suicide) attacks, and become one of them, but this is extraordinarily difficult to achieve. However, I would argue that the electronic search for the infinitesimal will identify some terrorists, but not the most dangerous. They understand that every credit card transaction is being fed into the system, and every car rental and every phone call is being tracked. Even if this isn’t true, they must assume it. Human penetration of IS by reliable sources with access to all levels of the organization is stunningly difficult and likely to fail as well. But if it works, it is the one way the enemy might lower its guard.

It is possible that this is actually being done systematically. Those who know don’t talk and those talk don’t know. I certainly have no idea. But as I survey the strategic options and disciplined nature of terrorists, I don’t see how automated collection of information can solve the problem. As for human intelligence, I fear that it is much like Will Rogers’ approach to German U-boats in World War I. He suggested that the Atlantic be boiled away, and the U-boats captured on the floor of the ocean. When asked how he proposed to do that, he said that he was a policymaker, and this was a technical problem.

Security cannot defeat terrorists. It mainly can determine timing. Electronic intelligence will capture some but not the best of the terrorists. Human intelligence requires people from the region prepared to undertake staggering risks, and doing it flawlessly. It probably can’t be done and if it has been, I have absolutely no knowledge of it. But we either do something like this or accept the periodic presence of terror.