My latest DIPLOMAT article on migration and refugees had this dismally prescient passage (emphasis added here):

According to the Office of The UN High Commissioner for Refugees (UNHCR), in 2014 on average some 40,000 people a day were driven from their homes by conflict or persecution and compelled to find somewhere else to live, either within their own countries or in another country. Many of them cross international borders as refugees or asylum-seekers. Millions more people are on the move trying to escape poverty: they want to cross international borders as normal ‘migrants’, people wanting the opportunity to live and work somewhere else.

Why is all this happening? Pick your causal factor. In my view one of the main drivers of global disorder is the growing availability of small but powerful weapons. This calls into question the ability of any state to maintain control.

Imagine what chaos would be caused if just a few small groups of terrorists armed with AK47s and grenades started attacking targets at random in different British towns and cities simultaneously. The scale of the firepower needed to suppress them would be huge, and the damage and disruption to life and property in the process almost beyond calculation. Within no time at all thousands of people would be racing to escape the battlefield.

You don’t have to spend long on YouTube to find astonishing quantities of horrible footage of different well-armed militia groups around the planet shooting up neighbourhoods and destroying local law and order. This in turn creates panic and forces people to flee their homes in colossal numbers. Syria and Libya are currently the grimmest examples of states slumping towards complete collapse, but there are plenty of others.

Paris last night gave us a horrible example of exactly this phenomenon: a small number of well armed fanatics doing colossal damage and killing scores of people within a matter of minutes, and far faster than any security services can respond to try to stop it.

Some thoughts.

On Twitter last night as the carnage unfolded I had a footling grumpy exchange with one Adam Smith @knkhtims who appears to be some sort of libertarian and therefore should be smart. Thus:

Imagine. All that nasty state snooping in fact helps keep us alive. Whatever next?

You realise France passed a bulk data collection/mass surveillance law 6 months ago, dont you? It didn’t help much did it.

You have absolutely no idea whether it helped or not. Don’t be absurd

It didn’t catch this incident. You’re a moron to argue otherwise.

* * * * *

Lo, the lugubrious @knkhtims promptly and rudely defaults to putting words in my mouth. I did NOT say or even hint that state intel surveillance caught this latest Paris outrage, as (of course) it did not. But the public only see the successful (from the terrorists’ viewpoint) outrages and do NOT see the plots that are intercepted or otherwise thwarted where nothing happens.

This is how surveillance works. There are simply too many possible terrorist suspects moving around closely and with human agents to follow them all. Not all terrorist suspects turn out to be terrorists. Not all plots are workable plots, or get taken to actual implementation. Not all people who plan and decide to commit killings go through with them. The whole problem is fraught with secrecy, intrigue, rumours, guesses and shadows.

In this vast sea of murky uncertainty, the security services are left to follow patterns of suspicious behaviour drawing on all sorts of intelligence sources, including email and telephone monitoring, as fast as they can (and tracking in person some especially ripe suspects) in the hope of finding out that a real plot is about to be unleashed and then stopping it.

So the fact that these attacks took place shows us nothing at all about French and wider surveillance. It may be that the French services were utterly inept and missed all sorts of obvious signals and clear tip-offs. It also may be that they did everything they sensibly and lawfully could do, and still these lunatics slipped through the net.

To put it another way. If a football goalkeeper saves 15 hard shots in a game but misses one especially good one that hits the net, that does not mean that the goalkeeper is a bad goalkeeper, or that goal-keeping as such ‘doesn’t help’.

That said, once the names/identities of some attackers in the mass murders last night are known, the agencies no longer need to look for broad patterns. They have hard facts to work with. can then focus fast on everything known about them and their movements going back days, months or years, and information will come flooding out. New insights will be gleaned. New suspects and risks will be spotted. As is happening now. Plus, all being well, new plots will be thwarted. And we mere cynical citizens won’t know how close we came to another catastrophe.

I have good reason to believe that former MI6 Chief Sir John Sawers will be giving a significant speech about these issues in the coming week or so. No doubt he will lay all this out with his customary rigour.

In short, as I said in my first Tweet in this exchange: state ‘snooping’ helps keep us alive. If some of us alas are killed, clever mass e-surveillance helps the authorities track down other potential murderers and look deeper into the ways such people operate and the supporting networks they have. It’s like a nasty disease: you can study it and try to find a cure only by having victims of the disease to treat.

Surveillance does not guarantee that we’ll stay alive. As Paris shows and the next rounds of Islamist massacres – and the massacres after that – will also show, nothing can do that.