Disinformation is on the rise, and Britain’s spies are on the back foot. Our intelligence leaders warn about election meddling, and our enemies are trying to undermine public trust in our national institutions. The United Kingdom needs to use covert means to disrupt anti-British activities at their source. That’s what Harold Macmillan said in the 1950s, shortly before becoming prime minister.

Over half a century later, in 2017, the Chief of MI6 made the same point: adversaries should be ‘playing in their half of the pitch not ours.’ And half a decade on from that, here we are again. This week’s intriguing peek into the secretive work of the National Cyber Force conjures the old saying: the more things change, the more they stay the same.

The National Cyber Force – a group of combined personnel from GCHQ, MI6, and the Ministry of Defence – released a document on Tuesday called ‘Responsible Cyber Power in Practice’, laying out the way they work. They conduct what are known as offensive cyber operations, meaning they disrupt Britain’s adversaries online by covertly hacking into enemy websites and communication channels. It’s the unacknowledged interference in the affairs of others. But for all the initial hype about cyberwar, the NCF’s work is not revolutionary. Cyberspace offers a new platform for old tricks. Propaganda, influence and sabotage.

The document talks of disrupting targets ‘with precision’, meaning there shouldn’t be collateral damage, but Clement Attlee, the post-war prime minister hardly known as a practitioner of secret statecraft, talked in the late forties of using MI6 to inflict what he called ‘pinpricks’ against Russia and China.

This is really just a pseudo-scientific phrase that repackages old ideas of covert operations for a new audience

It also talks of a British cyber operations being a responsible reaction – a ‘defence’ – against challenges posed by countries like Russia and Iran. But British covert action has always been framed as counterattack. A head of propaganda in the early Cold War once admitted that ‘Nobody wants to do anything unless they have to. If you find certain things going on that make you uncomfortable, then you start responding’. The UK would never do its own propaganda, obviously – only counter-propaganda.

This document reveals that the UK covertly exposes information to a range of audiences to sow confusion among our enemies. Today, that might mean presenting material directly to our enemies online. The analogue version involved forging enemy documents or laundering intelligence through fake think tanks, a favourite being the International Committee for the Investigation of Communist Front Organisations, or fake resistance movements, which often risked degenerating into a Monty Python-esque People’s Front of Judea fiasco. It didn’t (and still doesn’t) necessarily matter if the target intercepted the forgery. Exposure would confuse them, tie their intelligence services down in laborious mole-hunts, and induce paranoia. Paranoia breeds paralysis.

The most interesting-sounding part of the release is talk of a ‘doctrine of cognitive effect’, but again, this is really just a pseudo-scientific phrase that repackages old ideas of covert operations for a new audience. These sorts of techniques have long been used to disrupt the work of Britain’s adversaries. The legendary MI6 officer, Daphne Park, put it memorably: ‘once you get really good inside intelligence about any group, you are able to learn what the levers of power are and what each man fears from another and what each man will credit another of being capable of doing.’ Cognitive effects help intelligence services create antagonism within an organisation. It’s skilful shit-stirring, albeit ethical and targeted, whether conducted online or in the field. Not exactly brainwashing.

Measuring success in espionage is notoriously challenging. Small-scale, precisely targeted strikes appeal to bean-counting managers and their love of metrics, but it is difficult to determine their actual impact and strategic effect. Counting the number of websites disrupted or material planted is one thing, but working out what difference it makes is something else entirely. Cyberspace expands the potential reach and scale of our operations, but we must not conflate that with impact or significance. What difference do disruptive pinpricks make? How can the NCF say, for sure, that a certain covert action has resulted in a certain outcome? And do they prevent it becoming a game of whack-a-mole?

All this is difficult, but the NCF deserves some credit for opening itself up to challenge by publishing this document. Harold Macmillan, and plenty of his successors, would have been horrified by a public release like this. Whether its realistic approach to offensive cyber will leave senior ministers understanding what it can and cannot achieve is a very different matter. They’re always looking for a silver bullet.

‘Offensive cyber’ and ‘cognitive effects’ sound cutting-edge, and no doubt the technology is, but the fundamental principles remain the same: divide, disrupt, and sow ambiguity and paranoia. Remember the shock of the old.