What the Army's counter-drone doctrine puts first

There is a document that settles a lot of counter-drone arguments, and hardly anyone in the argument has opened it. Army Techniques Publication 3-01.81, Counter-Unmanned Aircraft System (C-UAS) Operations, dated 23 May 2025, superseding the August 2023 edition. The cover says "Approved for public release; distribution is unlimited." It is free on the Army Publishing Directorate site. It is 85 pages of body text before the glossary.

I served as a Counter-IED and Electronic Warfare Officer, which means I spent my time on the countermeasure end of exactly this problem, and I have written here before about what a jammer costs the people it protects. So my expectation, opening a 2025 revision, was a gear document. Small unmanned aircraft are the defining tactical problem of the decade, the money is enormous, and doctrine tends to follow procurement.

That is not what the document is. The equipment lives in an appendix, pages 67 through 84. The chapter that has the most to say about keeping drones from hurting you is Chapter 5, and inside it, passive defense runs from page 41 to page 49 while active defense planning runs from 50 to 54. Hiding gets more pages than engaging.

One sentence in paragraph 5-3 states the priority outright.

Passive air defense measures are the first line of defense against UAS.

That is the Army's current position, in its own publication, in a document you can download today. The first line of defense against drones is not a counter-drone system.

What passive defense actually means here

It is worth being concrete, because "passive defense" sounds like a euphemism for doing nothing. It is not. The doctrine lists the tasks units are supposed to train, and they are unglamorous in a way that I think is the entire point.

Operate at night or in limited visibility. Establish an early warning network on the radios the unit already has. Push warning down to the lowest echelon. Practice operational security. Use emission control "to limit electromagnetic and acoustic footprints." Disperse, because "dispersion may be the best damage-limiting measure." Maintain vigilance, particularly on convoys and at choke points. Then a set of survivability techniques: camouflage, concealment, hiding, blending, disguising, disrupting, decoys and deception, cover, and compartmentalization.

The texture of the hiding section is the part I would put in front of anyone selling a counter-drone product. It tells soldiers to "place mud on headlights and use camouflage nets to obscure the glare of windshields," and to "use noise blocking barriers and foam to lower the noise of operating equipment." Hardened overhead cover is prescribed for fighting positions, operations centers, fuel points, ammunition supply points and communication nodes, specifically to blunt "improvised munitions delivered by threat UAS."

Mud on headlights is a counter-drone measure. It costs nothing, it cannot be jammed, it does not require engagement authority, and it works on the drone you never detected. That last property is the one that matters most, and it is the property no active system has.

The emission-control line deserves its own beat, because it does double duty in a way that is easy to miss on a first read. Controlling your electromagnetic footprint reduces detection by enemy sensors, and the doctrine also credits it with reducing "mutual interference among friendly systems." That is my old problem stated in a passive-defense checklist. Your emissions are how you are found, and your emissions are how you break your own equipment.

The permission gate

Here is the structural fact that most coverage of counter-drone technology omits entirely. Defeating a drone is not a thing a system does. It is a thing a system is allowed to do, after several other things have happened.

Paragraph 4-55 opens the defeat discussion this way:

Defeat techniques begin once airspace deconfliction and target engagement authority has been passed down to the tactical level.

Read that as a precondition, because that is how it is written. Before defeat begins, somebody has to have deconflicted the airspace, and somebody has to have delegated engagement authority downward. The doctrine says elsewhere, in paragraph 5-35, that "hostile criteria for identification of UAS must be delegated as low as possible" and that "weapons control status for engagements against UAS must be as permissive as possible." Those are instructions to commanders to open the gate in advance, which tells you plainly that the gate is real and that closed is the default failure mode.

A vendor can sell you an effector. A vendor cannot sell you a permissive weapons control status. If the delegation has not happened before the aircraft shows up, your capability is a very expensive spectator.

Identification is the hard part, and doctrine says so

Between detection and defeat sits identification, and the document is refreshingly unwilling to pretend this is solved.

Paragraph 5-28 calls distinguishing friendly, neutral and hostile aircraft while weapons are being employed "a highly complex task," and then states the thing that makes it genuinely hard rather than merely difficult:

The same UAS may be flown by both friendly and enemy forces.

Both sides fly the same commercial quadcopters. There is no physical feature to key on, because there is no physical difference. That is why the doctrine leans on procedural identification, which "separates airspace users by geography, altitude, heading, time, and/or maneuver," and expects some combination of positive and procedural identification in practice.

The sensor problem is stated just as plainly. On visual aircraft recognition, paragraph 5-5 notes that because of their "small radar cross section and low/slow/kinematic profile, it is difficult to detect and identify using radar systems." I wrote a full report recently on why radar struggles to separate a drone from a bird, and it is a small vindication of that piece to find the Army's own doctrine conceding the point in a sentence and then telling soldiers to learn wings, engine, fuselage and tail by eye as a backstop.

Two operator details the trade press never mentions

Frequency fratricide is a planning item, not an accident. In the defeat discussion, the doctrine warns that "operational RF spectrums overlap with the control frequency of the UAS" and instructs that "key leaders must determine and mitigate frequency fratricide during defeat measures." I have lived that sentence. A jammer does not know whose receiver it is hitting, and the doctrine treats your own communications as something you must actively protect from your own countermeasure. Note also that it says to "continue jamming, until the UAS is inoperable," which is an admission that jamming is a sustained condition rather than a trigger pull, and everything else in your electromagnetic environment is inside that condition for its duration.

A downed drone is an explosive hazard before it is a trophy. This is the detail I would most like people outside the military to absorb. After an engagement, the doctrine has the battlespace owner conduct "a cordon and search to locate the down UAS," then submit "a 9-line report to request explosive ordnance disposal (EOD), and support to render safe the downed UAS." Only after EOD has rendered it safe can the aircraft be exploited for weapons intelligence.

So the promotional video where the laser kills the drone and everyone applauds is showing you the middle of the event. What follows is a cordon, an EOD request, a wait, and a piece of unexploded ordnance somewhere on your ground. Shooting a drone down over your own position converts an air problem into a ground problem. It is still usually the right call. It is not a clean one, and any cost comparison that stops at the price of the interceptor is not counting.

Worth noting too: the doctrine's own list of physical defeat methods is broader and stranger than the marketing suggests. Explosive munitions, small arms, projectiles, entanglement, streamers, spray foam, capture nets, directed energy, laser, and high-power microwaves. Spray foam and streamers sit in the same list as directed energy, which tells you the Army is not committed to an elegant answer.

The framing that carries the whole document

The introduction does something I did not expect from a 2025 revision. It deflates its own subject.

Enemy UAS is not a unique threat. The actions Soldiers take to counter-unmanned aircraft systems are not very different than actions taken to counter any other air threat such as an enemy fixed-wing or rotary-wing aircraft.

That is a document arguing against its own novelty, which is usually a sign of people who have thought about a problem for a while. It goes with two other framing claims from the same page: that C-UAS "is not a stand-alone effort or the sole responsibility of any warfighting function or branch" but rather "the responsibility of every Soldier and unit," and that it "is not just when unmanned aircraft vehicles are flying, but also takes place 'left of launch'" through intelligence analysis and targeting.

Put those together and the doctrine is making a claim that runs directly against how the problem is usually sold. Countering drones is mostly not an equipment category. It is dispersion, discipline, warning networks, emission control, delegated authority and a threat-analysis process, with effectors as the layer you reach when all of that has already failed.

What I could not confirm, and what I am not claiming

Everything above is quoted from one document that I downloaded from the Army Publishing Directorate and read: the May 2025 ATP 3-01.81. Where I quote, the words are the Army's.

I did not compare it line by line against the superseded August 2023 edition, so I am not claiming that any particular emphasis here is new. The priority of passive defense may well be long-standing doctrine rather than a 2025 change, and I would not want a reader to take "the Army now says" from a piece that has only read the current version.

One small documentation quirk, offered as an observation rather than a finding: the introduction states that the publication "contains five chapters and three appendices," then lists seven chapters, and the table of contents shows seven chapters and a single Appendix A. The body matches the table of contents. I mention it only because it is the kind of thing that tells you a document was revised under time pressure, and because I would rather report what I actually saw.

This is unclassified public doctrine. It describes techniques at a level appropriate for public release, and it is not a targeting guide, a tactics manual for anyone's specific site, or a substitute for the training and authorities the document assumes. Nothing here is advice about engaging any aircraft. Civilians in particular should read my earlier report on who can legally stop a drone, because almost every technique named above is a federal crime when a private party does it.

The signal

Three things to carry out of this.

First, if you are evaluating counter-drone capability, ask where the authority lives before you ask what the effector does. Doctrine gates defeat behind airspace deconfliction and delegated engagement authority. A procurement decision cannot produce either one, and a system that is not cleared to fire is not a defense.

Second, the cheapest measures are the only ones that work against the drone you did not detect. Detection is a precondition for every active response and for none of the passive ones. That asymmetry is why doctrine ranks them the way it does, and it survives translation to any protection problem, including the ones I work on now that are nowhere near a battlefield.

Third, read the primary document. It took one download and an afternoon. A large share of public argument about counter-drone technology is conducted between people quoting trade coverage of press releases, when the Army has published its actual position, in plain English, approved for public release, for free.