Small Kill Teams are back: New Lessons from Ukraine’s Fortified Fronts

Cover Photo Credit: Reuters/Kuba Stezycki

Russia’s ongoing invasion of Ukraine continues to deliver hard lessons for military planners. The war’s third and fourth years have demonstrated a decisive shift away from the historical set-piece, maneuver-heavy battles toward attritional contests along deeply fortified belts.

Armor still matters (make no mistake, the tank is far from dead), but large mechanized thrusts are rarely decisive when ubiquitous sensors, layered minefields, and precision fires render mass conspicuous and vulnerable. Instead, tactical initiative increasingly resides with small units, the sections/squads and small detachments conducting simultaneous probing assaults along dispersed sectors. 

When one probe opens a seam, higher-quality forces surge through the “proven route,” exploiting at tempo before the defender can reconstitute. This reality is not a fad; it is a structural feature of today’s transparent, drone-saturated battlespace, and it should shape how allied forces train, equip, and lead their small units.

This battlefield transparency greatly punishes mass formations. Commercial and military ISR, pervasive FPV drones, and networked fires expose any concentration of vehicles or troops. RUSI fieldwork in late 2024 and early 2025 describes an environment in which unmanned systems and electromagnetic warfare (EW) rapidly detect and attrit larger groupings, forcing both sides toward dispersed, low-signature actions. CSIS analysis echoes this. Drone innovation and countermeasures have driven a steady move toward smaller, agile teams able to survive and adapt under constant aerial observation.

Because of this, layered defense still imposes a mobility problem that forces these teams to solve the problem from the bottom up. Defensive belts, including trenches, wire, mines, and dragon’s teeth demand meticulous breaching, route proofing, and local dominance of micro-terrain. RUSI’s 2025 tactical update notes that Ukrainian adaptation created a 15-km-deep “belt of attrition” that slowed Russian operational momentum and forced assaults to devolve into small, sequential fights over tree lines, dachas, and trench nodes.

ISW’s daily assessments across 2025 reinforce that Russia rarely attempts company-plus mechanized assaults; instead, it pushes numerous fire-team to squad-sized groups, often supported by drones and artillery, to nibble positions and search for weak seams.

This small, smart, and many approach is further incentivized by the cost and scale of such actions. Ukraine plans multi-million-unit FPV production in 2025, translating into constant local strike pressure that rewards dispersed maneuver and punishes large signatures. In this economy of force, section-level actions can fix, deceive, or fracture a defensive node cheaply - creating opportunities disproportionate to their size.

Ukrainian soldiers are seen in a recently recaptured village in the northeastern Ukrainian region of Kharkiv. (Mstyslav Chernov/The Associated Press)

But how does this work on the ground? Recent Ukrainian practice along the Donetsk and Kupiansk axes illustrates a repeatable pattern. 

First, simultaneous probes by sections or small platoons are launched across widely separated points, often at night or under EW cover, to force defenders to reveal fires and drone patterns. ISW has repeatedly documented this “thousand cuts” approach, with hundreds of daily contacts dominated by small infiltration teams rather than battalion-level pushes.

Next, rapid exploitation when a probe breaks through or finds a lightly held trench segment. Better-trained assault elements (air assault, marines, or select mechanized troops) move along the proven route—pre-cleared lanes through mines and observed dead ground—before the defender can reposition. RUSI’s aforementioned field notes describe this transition from dispersed probing to focused exploitation as the central mechanism for gaining ground under constant drone threat.

Finally, assault elements hold and harden. The seizing element immediately flips the position: drones to overwatch, FPVs for counter-counterattack, and hasty obstacles to resist the inevitable local counterpunch. ISW reporting indicates that even successful gains are modest, limited to tree lines, trenches, hamlets, but cumulatively significant along a 1,200-km front.

A notable case in late 2025 reporting described Ukrainian platoon-led actions recapturing villages near Dobropillia via small-unit advance, close drone integration, and quick exploitation with heavier assets - no massed armor assault required. Parallel open-source reporting also documents Russia’s own small, decentralized assault groups - sometimes on motorcycles with improvised drone cages - underscoring how both sides converge on similar low-signature solutions.

While technology and context have changed, core small-unit doctrine remains relevant, if aggressively adapted. US Army manual ATP 3-21.8 (Infantry Platoon and Squad) emphasizes decentralized initiative, enemy-oriented movement, and leaders who maneuver by micro-terrain with fires and obscuration. The 2024 update reinforces section/platoon mastery of battle drills, battle-tracking, and rapid consolidation - precisely what Ukraine’s attritional environment demands.

Additionally, breaching fundamentals at the section level are being scaled. Classic SOSRA (Suppress, Obscure, Secure, Reduce, Assault) is no longer exclusively a combined-arms company activity; it’s a continuous, small-unit habit executed with FPVs (suppress/reduce), smoke/UAV-dropped obscurants (obscure), and micro-teams clearing lanes to create the “proven route.” RUSI’s fieldwork stresses realistic drills under drone/EW pressure rather than rote adherence to past templates.

This pressure also creates mission command and communications problems. Small-unit success now hinges on leaders able to act on fragmentary ISR, under intermittent comms, and with EW-driven ambiguity. CSIS and RAND emphasize building resilient C2 that tolerates degraded networks - another argument for well-trained junior leaders empowered to exploit fleeting opportunities.

Members of Ukraine's 3rd Assault Brigade. (Diego Fedele/Getty Images)

Now what does this mean for military trainers and doctrinal advisors? For NATO and partner militaries, the Ukrainian experience in the last 12 months points to five priorities. 

First, squads and teams need to become lethal “combined arms” elements in their own right. Integrate organic sUAS/FPV pilots, EW spotters, and breaching kits at section level. Train leaders to pair micro-ISR with immediate fires (tube, loitering, or FPV) to isolate trench nodes before assault. CSIS interviews with Ukrainian units highlight the speed advantage when drone feeds and strike options are co-located with the assault leader, not hoarded at higher echelons.

Second, the concept of simultaneous probing should be holistically institutionalized by commanders. Build SOPs for launching dispersed, time-bound probes that map enemy fires and EW in near-real time. ISW’s assessments show this tactic defines daily contact density along the front; it should be routine in allied field training.

Third, units need to rehearse and become masters of “proven route” exploitation. Teach squads to convert a local success into a lane: mark, protect, and pass follow-on elements, then flip to defense in minutes. The RUSI team also notes that units that drill this transition under drone threat are the ones that hold what they seize.

Next, the small units at the lowest levels need to become hardened against the ever-present drone and EW threat. Practice movement with anti-FPV screens, decoys, and signature discipline (thermal/EM). Expect EW loss and train leaders to operate on commander’s intent, triggers, and time hacks rather than constant comms. RAND’s 2025 synthesis argues the United States, and by extension the rest of NATO, should adapt small-unit C2 and protection to Ukraine-like conditions rather than refighting legacy scenarios.

Lastly, leaders should internalize the measurability of micro-terrain control and survivability. Success in a fortified fight is incremental, such as one tree line, one trench, or one culvert, achieved without prohibitive losses. AP reporting from late 2025 cites Ukraine’s shift to small, mobile assault groups and 160–190 daily engagements as the new normal, and as such the new training metrics must mirror that reality.

From Chasiv Yar to the lower Donetsk front, the last year of fighting shows that the unit of decision has shrunk. Squads and platoons, tightly integrated with drones, EW, and immediate fires, are the tip of the spear that pries open seams in fortified belts. Their dispersed probes create dilemmas; their rapid exploitation along proven routes converts tactical opportunity into positional gain. 

Large armored assaults will return only when protection, deception, and mobility can consistently outrun battlefield transparency; until then, professional militaries should invest in making small units smarter, tougher, and faster than the enemy’s.

For allies and partners, that means elevating small-unit mastery from a training line item to an operational center of gravity. Doctrine already points the way; Ukraine’s recent experience tells us how urgently to apply it.