In Havana in late 2016, American diplomats began hearing a sound they couldn’t place. It was described as pressure in the head, or ringing in the ears, followed by headaches and trouble concentrating that did not go away. Over the next few years more than a hundred cases were documented in several countries, with neurological findings that persisted after the acute symptoms faded.
Then a different explanation arrived. A report commissioned to review the cases suggested the sound matched a cricket — Anurogryllus celerinictus — and that the injuries might have been psychogenic. The Army’s discussion of the cases was quietly removed from public view.
I’ve thought about that sequence more than the diagnosis itself. You hear a sound, you get sick, you look for a weapon, and you are offered a cricket. Whatever actually happened in those rooms, the uncertainty is the point that stays with you. A conflict where you can’t agree whether there was an attack, let alone who ordered it, is hard to defend against — and hard even to admit as a conflict.
Fifth-generation warfare is a clumsy name for that kind of problem.
The definition that refuses to settle
The phrase started in 2003, when analyst Robert Steele suggested there was a new kind of war beyond the one William Lind and his co-authors had described in 1989. Lind had argued war was moving from massed manpower to firepower to maneuver, and then to a fourth generation where the state’s monopoly on fighting eroded and decentralized insurgents could tie down a superpower. Steele thought something else was emerging after that. Lind, for his part, rejected the addition the following year, saying the fourth generation hadn’t fully arrived yet.
That disagreement never really resolved. There is still no widely agreed definition and no joint doctrine publication that codifies it.
Daniel Abbot, editing The Handbook of 5GW in 2010, offered the most honest formulation I’ve found: “The very nature of Fifth Generation Warfare is that it is difficult to define.” He added, more plainly, that it is a war of information and perception. Others have phrased the same idea as the deliberate manipulation of an observer’s context in order to get a desired decision, or, in the compressed version that stuck with me, a war where you might not know you are losing it because you don’t know you are in it.
The useful way I think about the generations is not as a timeline where one replaces the last, but as overlapping layers that get added. First-generation wars were about putting bodies in line. Second about putting metal on target. Third about moving faster than the other side could orient. Fourth about making political will the target and using any mix of political, economic, social, and military pressure to erode it. Fifth keeps all of that but moves the primary contest to perception itself.
What makes that move different is not that propaganda is new — it isn’t — but that the tools for testing and shaping perception are now data-driven, cheap, and fast. An advertising platform can build a model of what holds a particular person’s attention for an extra half second. The same model can be used to see what makes that person suspicious, indignant, or exhausted. When those loops are measured in milliseconds, you don’t need to persuade an entire country. You can nudge a small group at the right moment, see what happens, and adjust.
From winning information to shaping meaning
A distinction the Army’s Cyber Defense Review has tried to make — and that a recent synthesis of 5GW literature highlights — helped clarify this for me. Information warfare is the battle for information, the contest for electrons and access in the electromagnetic spectrum. Cognitive warfare is the battle of information, the contest over what those electrons end up meaning.
In practice the two are usually paired. A cyber operation that steals or leaks emails wins information. The story that gets wrapped around the leak — who it is said to incriminate, what it is said to prove about the other side’s illegitimacy — shapes meaning. The first can be measured in data exfiltrated. The second shows up in what people believe is true about their own institutions.
That is why attribution is more than a technical puzzle. In a kinetic war you generally know who fired. In a well-executed influence operation you may not know whether a message was amplified by a neighbor who believes it, a commercial data broker who sold a list, or a state actor who seeded the narrative. Grey Dynamics puts it bluntly that simply understanding who is behind a 5GW attack can be impossible. When the Economist or the Wall Street Journal later maps the operation, they are often reconstructing it from fragments — cloned news sites in the Doppelgänger operation of 2023, deepfakes that are caught only after they have circulated, networks of accounts that behaved as if they were coordinated but were hard to tie to a single sponsor.
I’ve come to care less about single dramatic examples than about cumulative pressure — the slow change in how a group weighs options over time. That is also why the usual scoreboard — how many accounts were taken down, how many leaks were proven authentic — misses the larger question of what an information environment is training people to become.
Where it already lives
If the category still sounds theoretical, the institutions have stopped treating it that way.
NATO’s Allied Command Transformation now maintains a standing Cognitive Warfare program, and its chief scientist released a new report on the subject in January 2026 describing cognition as a domain alongside land, sea, air, space, and cyberspace. The language is deliberately spare: the aim is to affect not only what an adversary knows but how they think and how they will to act.
In Washington, the 2026 National Defense Authorization Act directs the Secretary of Defense to define cognitive warfare, identify who inside the Department owns it, and assess the value of “narrative intelligence” by the end of March 2026. The small detail that Congress felt it had to order a definition tells you how dispersed responsibility still is. The Army talks about information operations, the Air Force talks about data-saturated multi-domain environments, and the analysts in between argue about the line between hybrid warfare and gray zone conflict.
On the domestic side, the Cybersecurity and Infrastructure Security Agency has been asked to do more — election security, critical infrastructure, public cyber literacy — while facing political and resource strain. That mismatch matters because cognitive effects do not stop at a network boundary. An attack on a water treatment plant can be both a technical incident and a message about whether the government can keep water safe. The deeper effect is not the outage. It is the erosion of trust that makes the next shared task harder.
Even the communications layer is being rebuilt with this in mind. The Department of Defense released a Private 5G deployment strategy in late 2024 that is partly about speed and partly about resilience — making it harder for an adversary to inject, delay, or deny information at the transport layer. None of that prevents a convincing deepfake from spreading on the application layer. It just makes the underlying pipes less fragile.
What winning quietly asks of us
If the best way to win is to arrange things so the other side makes your preferred decision on its own, then the defense cannot be purely technical. Firewalls, private networks, and better detection of coordinated inauthentic behavior all matter, and I don’t mean to minimize them. But they defend the contest for information. They don’t, by themselves, settle the contest over what it means.
That second contest happens in people.
It is tempting to propose a filter — better AI detection, more content moderation, more media literacy slides. Some of that will help, though every filter creates a new argument about who controls the filter. The more durable response is less centralized and less glamorous. It is the old set of protections that make a person harder to reroute: habits of attention, local knowledge, institutions small enough to verify.
I notice this in my own use of the phone. The same device that lets me check a fact in seconds makes it harder to sit with a question for more than a minute. The feed rewards quick classification — ally or adversary, serious or absurd — before I’ve finished reading. Over months that trains a reflex. The world sorts itself into familiar villains and familiar victims, and the most useful response always seems to be sharing one more piece of evidence with people who already agree with me.
Fifth-generation conflict benefits from that reflex precisely because it doesn’t need to invent it. It can simply amplify what already moves quickly.
The alternative is not to log off and wait for the institutions to catch up. It is to cultivate the small practices that restore judgment. Knowing a neighborhood, a workplace, a congregation, a physical discipline — any setting where information has costs and where you can check a claim against people you know — gives you a baseline that a synthetic narrative has to work harder to displace. Verifying before amplifying is a modest discipline, but at scale it functions like herd immunity. Keeping limits on what data you broadcast — location, contacts, routines — shrinks the surface that can be modeled and nudged.
None of this guarantees you will see the operation while it is happening. The best defenses against perception manipulation are not dramatic. They are what the worldview that guides this site would call virtues formed through repeated action — attention, truthfulness, restraint, willingness to be corrected — and they are valuable even apart from any adversary.
There is a reason Abbot’s line about the most successful wars never being identified has endured. It captures a change in how power can be exercised. Territory is expensive to occupy. Machines are expensive to replace. Perception, by contrast, can be shaped at the margin with tools that are already rented out for advertising. If you can shift the context in which a few thousand decision-makers interpret an event, you do not need to control the event.
That also explains why the institutions are struggling to name it. A phenomenon that crosses the line between war and peace, between crime and influence, between foreign and domestic in a single afternoon does not fit neatly into one agency’s charter. Asking Congress to produce a definition is a small step toward admitting that gap.
I don’t think the right conclusion is to treat every confusing episode as a covert operation. That way of thinking is itself a form of vulnerability — every cricket becomes a weapon, every coincidence becomes evidence. The healthier suspicion is closer to housekeeping. Keep your network patched, but also keep your judgments patched. Notice what makes you feel rushed, righteous, or certain that the other side is not merely wrong but illegitimate. Ask where that feeling came from and whether someone benefited from speeding it up.
The monk’s old remedy for distraction was not elaborate. Stay in the cell. In more ordinary terms: remain where you have good reason to remain, do the next real task that belongs to you, and let the algorithm wait. A war that depends on stealing attention is partly defeated by people who learn, quietly and without announcement, to give their attention to what they have already chosen.
That will not sound like a defense strategy. But for a form of warfare that wins by being unnoticed, the most reliable defense may be a life that is less easily moved.