Well-executed spying is an essential safety valve. But the NSA has got ahead of its friends

So the world now knows that the US has definitely been spying on the mobile phone calls of Angela Merkel, François Hollande, David Cameron and most probably the leaders of every other one of its closest allies. Everyone suspects these countries attempt the same back just as surely as do the US’s strategic opponents, Russia, China, Iran and North Korea.

This can be summarised thus; the US spies on its friends and allies who also spy on their friends and allies. Everyone spies on their enemies.

Astonishing, who knew?

Despite Angela Merkel's ridiculous public show of outrage, every leader knows that this arrangement is not only a long-established part of international relations but is an essential communications back-haul, something that has almost certainly saved humanity from countless wars and tens of millions of dead.

Knowledge is power but it is also a huge risk if an imbalance is created, that is if one side knows more than the other or starts to believe that it knows less. The currency of detente during the Cold War was a measure of certainty, the guarantee that if a short-term technological imbalance appeared the other side would have a way of finding out about it. It was always in the interests of both sides that each knew enough to feel secure and that is why spying was turned from Victorian intrigue into an essential part of the international system without which we’d all probably be dead.

Of course, countries want a certain amount of short-term cover and this is why every important government building and diplomatic mission in the world has a ‘secure room’ (radio shielded with an encrypted and probably now quantum-encrypted link) in which the day-to-day laundry of a country and leader can be moved around the need-to-knows. Think of these rooms as a kind of modesty blanket.

But if spying is a necessary part of the international system, why the incredible fuss? The likely answer is that NSA systems including Prism have by being so advanced introduced a dangerous degree of asymmetry that upsets the delicate balance of ‘you know what I know but I also know that you know this’ on which world relations depends.

Put another way, the US has got ahead of its friends and enemies and - worse - allowed this short-term advantage to become known about.  ‘You know what I know but I don’t necessarily know what you know’.

Ironically, this doesn’t much bother the US’s enemies who are building their own military equivalents of Prism and have had decades of Cold War experience in which to finely judge when an advance by either side risks creating a dangerous imbalance. Germany and France are a different matter because they have falllen behind.

It’s important to draw a major distinction between this and the NSA’s surveillance on ordinary citizens using Prism because that works by different rules in which the state has set out to make permanent the information imbalance between its people and its spies. That is dangerous for other reasons including the huge undermining of public trust that only the foolhardy don’t believe will have some negative consequences down the line.

What is important is that citizens, countries, organisations know what is known about them and use that to gauge where the boundaries of knowledge, information and power lie. US officials have made it clear that the US administration believes Edward Snowden’s revelations have damaged the US and on the basis of this week’s sharp words from Angela, they are probably right. Her public annoyance is an unprecedented event in US-Germany relations.

The moral is that if you end up knowing more the greatest skill is required in order to make it appear that you know less.  Spying is a safety valve the world needs. Knowledge carries with it enlightenment and risk in equal measure.