COLUMN: Kupyansk Under Pressure — Radkivka Falls, the Ukrainian Bridgehead Holds

COLUMN: Kupyansk Under Pressure — Radkivka Falls, the Ukrainian Bridgehead Holds

Introduction: Radkivka, a name that rings like an alarm

A town we thought we held

On June 22, 2026, a Russian source linked to the West Forces Group announced the capture of Radkivka, a village located north of Kupyansk in Kharkiv oblast. It was not a complete surprise — geolocated footage published on June 20 and 22 already showed Ukrainian forces striking Russian positions in northern Kupyansk and Kurylivka, following what the Institute for the Study of War (ISW) describes as Russian infiltration missions.

But behind this village name that most Western readers have never heard of, something larger is playing out: the survival of the Ukrainian bridgehead east of the Oskil River, that defensive line protecting Kupyansk from potential encirclement. The central question remains: how far can Russian forces advance before the line gives way?

The Ukrainian spokesman sounds the alarm

Colonel Viktor Trehubov, spokesman for Ukraine's Joint Forces, confirmed that the Kupyansk direction constitutes the second most active sector of the front, just behind Lyman. Russian troops are actively trying to reduce the Ukrainian bridgehead on the left bank of the Oskil, while simultaneously increasing pressure toward Kozacha Lopan from the border settlement of Hraniv.

According to RBC Ukraine, the Russians are multiplying their attempts to expand their zone of control east of Sumy, even though Ukrainian defenders continue to hold the settlements. This is not a breakthrough — it is a war of attrition fought with a teaspoon. And it is precisely this style of combat that grinds defenders down.

The geography of danger: understanding the Oskil bridgehead

A defensive corridor under constant pressure

The Oskil River has served for months as a natural line of demarcation between Ukrainian and Russian forces in the Kupyansk region. The Ukrainian bridgehead — that foothold on the left (eastern) bank of the river — is essential for maintaining defensive depth and preventing Russian forces from approaching the city of Kupyansk directly from the east and northeast.

The ISW has documented for months Russia's attempts to eliminate this bridgehead by intensifying assault operations on the left bank of the Oskil. The capture of Radkivka follows this same logic: reduce Ukrainian maneuver space, compress the pocket, and force a retreat or surrender of advanced positions.

Glide bombs against drones and logistics

The ISW notes that Russian forces have intensified their FAB-500 glide bomb strikes against Ukrainian drone operators and logistics corridors in the Kupyansk direction. Geolocated images published on June 19 show Russian FAB-500 strikes hitting a suspected Ukrainian drone control point at Monachynivka (northwest of Kupyansk). On June 20, four more glide bombs targeted a bridge on the H-20 Kupyansk-Chuhuiv road west of Hrushivka.

The logic is clear: by cutting Ukraine's ability to surveil and strike via drones, and by degrading logistics bridges, Russia seeks to weaken Ukrainian resistance ahead of ground assaults. It is a local area-denial strategy applied at a tactical scale of just a few square kilometers.

Infiltration as doctrine: the Radkivka method

Small groups as urban scouts

The Russian tactical approach in the Kupyansk direction is not that of massive armored charges — it is patient infiltration. For months, small Russian groups of two to nine soldiers have been penetrating urban areas, often at night, using abandoned pipelines, rubber boats on the Oskil, or simply exploiting blind spots in Ukrainian defenses.

On June 22, 2026, geolocated images again showed two Russian soldiers infiltrating the center of Radkivka — before the Russian source claimed total capture of the village. This micro-infiltration is followed by consolidation: small groups hold strategic points until reinforcements arrive or until they are eliminated by the Ukrainians.

The Ukrainian response: striking infiltration at its source

Ukrainian forces have adapted their response to this tactic. Images published on June 20 and 22 show Ukrainian strikes on Russian positions in northern Kupyansk and northern Kurylivka — executed after detected Russian infiltration missions. The response is reactive, but coordinated: detect, locate, neutralize.

Colonel Viktor Trehubov stressed that Russian forces are suffering significant losses in this direction despite their repeated attempts. On June 28, 2026, the Ukrainian General Staff recorded only 3 Russian attacks in the Kupyansk direction on the day of June 27, all directed at the village of Novoplatonivka — a sign that tactical intensity fluctuates from hour to hour.

Kupyansk in the broader context of the summer 2026 front

The second hottest sector according to Trehubov

Colonel Trehubov's statement is key to understanding Ukrainian defensive priorities in the summer of 2026: Kupyansk is the second most active sector, trailing only Lyman. This ranking reflects a brutal front-line reality — the Russians are concentrating their efforts along a handful of specific directions, seeking a breakthrough wherever defenses are most worn down.

Of the 241 engagements recorded by the Ukrainian General Staff in the 24 hours of June 27, 2026, the Lyman front logged 16 Russian breakthrough attempts, Huliaipole recorded 29, and Kostyantynivka saw 21. These figures illustrate the overall pressure: the Russian army strikes simultaneously along a dozen directions, hunting for the weakest link.

Russia attempts to expand its control east of Sumy

Alongside the pressure on Kupyansk, Russia is attempting to widen its zone of control east of the Sumy region, according to RBC Ukraine. Ukrainian defenders are holding the settlements for now, but the proliferation of active fronts places enormous logistical and human pressure on Ukrainian forces already engaged across numerous axes.

President Zelensky declared that Russian troops had attempted offensives in 12 directions but had lost the initiative nearly everywhere — noting that slow advances occur only in two or three zones where Russia has concentrated enormous amounts of personnel and equipment. Kupyansk is one of those zones.

The long view: Radkivka in the memory of the conflict

A name that recurs since 2023

For observers who have followed this conflict from the start, Radkivka is no newcomer to war bulletins. The village appears in ISW reports dating back to January 2026, when Russian forces were already pushing toward Radkivka from north of Kupyansk. In September 2025, it was one of three villages — along with Kindrashivka and Holubivka — identified as the strategic triangle upon which the security of the Ukrainian bridgehead depended.

In September 2025, the commander of the Achilles Regiment, Yuriy Fedorenko, explained that Russian attempts to cross the Oskil in the Radkivka area by boats and rafts succeeded roughly two times out of ten. Six months later, Russian persistence appears to have shifted the balance of power in this particular village.

The December 2025 liberation and the return of pressure

The winter of 2025–2026 saw Ukrainian forces recapture part of the ground lost around Kupyansk. The ISW documented the liberation of at least 183 square kilometers between December 11 and 25, 2025, in a countermovement that stabilized Ukrainian control over the city. But that stabilization was fragile, and by spring 2026, Russian pressure had resumed.

The cycles of recapture and loss in this area illustrate a fundamental truth: in a war of attrition, tactical gains are reversible. Radkivka has changed hands multiple times in less than a year. That is not an anomaly — it is the norm in this type of conflict.

FAB-500s and the drone war: the ground-level air duel

Russian glide bombs are redrawing the battlefield

Russia's intensive use of FAB-500 glide bombs in the Kupyansk direction represents a significant tactical evolution. These munitions — guided by GLONASS and potentially by artificial vision systems — allow Russian aircraft to strike from a safe standoff distance while maintaining sufficient precision to destroy key infrastructure: bridges, control points, buildings occupied by drone operators.

The June 20 strike on the H-20 road bridge is particularly revealing: by targeting Ukrainian logistics on that axis, Russian forces seek to slow troop rotations and resupply runs that allow the Ukrainians to maintain their bridgehead. It is a textbook application of aerial interdiction, applied at a scale of just a few kilometers.

The Ukrainian response through FPV drones

In response to Russian FAB-500s, Ukrainian forces rely heavily on their FPV drones to neutralize infiltration groups and strike consolidated positions. Images published on June 20 and 22 show Ukrainian drone strikes on Russian positions in northern Kupyansk and Kurylivka — an asymmetric response capability that partially offsets Russia's numerical superiority.

The challenge for Ukraine is keeping this drone stream operational even as Russian strikes specifically target operators and their equipment. This war within the war — Russians targeting drone operators, Ukrainians targeting infiltrators — defines the daily texture of combat in this direction.

Kurylivka: the southeastern flank under parallel pressure

A secondary axis that could become primary

Beyond Radkivka to the north, Russian forces are also maintaining pressure on Kurylivka, southeast of Kupyansk. This settlement has been the site of repeated Ukrainian strikes in June 2026, following documented Russian infiltration missions. The geography is significant: Kurylivka sits on approach routes toward Kupyansk-Vuzlovyi, the railway junction that forms a crucial logistics hub.

If Russian forces succeeded in advancing simultaneously from the north toward Radkivka and from the southeast toward Kurylivka, they would be in a position to dangerously compress the Ukrainian logistics corridor. This is precisely the scenario the Ukrainian command is trying to prevent by maintaining active defensive strikes along both axes.

The role of Novovasylivka in the Russian maneuver

Russian milbloggers reported on June 20 Russian advances at Novovasylivka (northeast of Kupyansk), in addition to Radkivka. These advances to the northeast create dual pressure on the Ukrainian flank — forcing defenders to spread their limited resources across multiple simultaneous contact points.

The ISW notes that Russian forces conducted limited infiltrations in the northern and northeastern parts of Kupyansk, but that these infiltrations do not constitute stabilized advances. The nuance matters: infiltrating a village does not mean controlling it durably. The difference between an infiltration and a capture depends on the ability to consolidate and hold under Ukrainian counterattacks.

Trehubov and the doctrine of calculated transparency

A spokesman facing the obligation to tell the truth

Colonel Viktor Trehubov has become one of the most reliable voices from the Ukrainian command regarding the Kupyansk direction. His communication stands out for its relative transparency about difficulties — acknowledging that Kupyansk is the second most active sector is no small concession in a war where information is itself a weapon.

In May 2026, Trehubov had already publicly declared that the situation on the Oskil bridgehead was "difficult" but that Ukrainian forces were holding. This continuity in messaging — difficult but tenable — is itself strategic information: it signals to Western partners that the line is not at risk of immediate collapse, without denying the reality of the difficulties.

The sector ranking: a piece of strategic information

Ranking Kupyansk as the second most active sector, behind Lyman, is a deliberate communications decision. It draws attention to a sector that receives less media coverage than others — Kostyantynivka, Pokrovsk — while signaling that support needs are real.

Among the 241 engagements on June 27, the Lyman direction was involved in 16 Russian assaults, and the Sumy/Slobozhanshchyna direction in 15 attacks. Kupyansk, with 3 attacks specifically that day, might appear less intense — but quiet days will alternate with days of massive assaults. Pressure is not constant; it is cyclical.

The human cost of pressure on the bridgehead

Losses on both sides in anonymity

No precise casualty figures are available for the Kupyansk direction in June 2026 — Ukrainian data is classified and Russian figures are notoriously inaccurate by common knowledge. But observed patterns allow for an estimate: in a zone where Russian forces conduct daily infiltrations and suffer drone strikes in return, casualties are continuous on both sides.

What makes the war at Kupyansk distinctive is that urban and peri-urban combat generates disproportionate losses for the attacker. The Russians send reconnaissance groups that are eliminated by FPV drones before even reaching their objectives. This high sacrifice rate is consistent with current Russian doctrine: using poorly trained conscripts as expendable scouts.

Civilians held hostage by the front

Thousands of civilians still reside in settlements near the front in the Kupyansk region. In January 2025, the head of the Kupyansk district military administration, Andriy Kanashevych, reported that approximately 1,660 residents of Kurylivka, Kindrashivka, and neighboring communities remained on the left bank of the Oskil. Evacuation operations continue but run up against Russian drones and artillery striking evacuation routes.

Every FAB-500 strike on a logistics bridge is not only an attack on Ukrainian military capacity — it also undermines the ability of civilians to flee combat zones. This dual tactical and humanitarian dimension is deliberate within Russian strategy: making life unbearable to force Ukrainian civilians to accept their fate.

Russian pressure across Kharkiv: a regional context

Governor Syniehubov and the regional reality

The Russian offensive in the Kupyansk direction is part of broader pressure across the entire Kharkiv oblast. Regional governor Oleh Syniehubov documented in the weeks preceding June 22 Russian strikes against residential areas — strikes that killed or wounded several people with no apparent military rationale.

Russian forces had not advanced beyond the northern outskirts of Kozacha Lopan since late April 2026, according to the ISW — a sign that Ukrainian defenses in northern Kharkiv are holding. But the pressure is constant, and every successful strike in this area sends a signal to the civilian population: you are not safe, even far from the direct front lines.

Kozacha Lopan and the diversionary strategy

A source analyzing the Russian North Forces Group reported to the ISW that Russian forces regularly send small numbers of soldiers to attack Kozacha Lopan in order to "create the impression of constant combat" in the area — a tactical diversion designed to pin Ukrainian reserves that could otherwise be repositioned toward more critical zones.

This diversionary tactic is sophisticated in design: it requires no real advance, only sufficient activity to prevent the Ukrainian command from reassigning the units defending that sector. In a war where human reserves are precious on both sides, this economy of threat is a form of asymmetric warfare accessible even to a numerically superior army.

Western partners facing the reality of Kupyansk

Material support that must adapt to ground-level needs

The Kupyansk direction illustrates a major challenge for Ukraine's partners: delivering not only spectacular weapons systems like F-16s or long-range missiles, but also the munitions, drones, and spare parts needed to wage a daily war of attrition. Russian FAB-500s demand specific countermeasures — counter-drone systems, early-detection radar, and enough NASAMS or Patriot systems to cover rear areas.

Both the Biden administration and the Trump administration have provided significant weapons deliveries to Ukraine, but the flow is never fast enough for the needs of the Kupyansk front. Every week of delay in delivering counter-drone systems translates concretely into Ukrainian drone operators left vulnerable to Russian retaliatory strikes.

NATO and the question of tactical red lines

The Kupyansk zone also raises the question of use-of-force authorizations for Western weapons. ATACMS missiles have been cleared to strike targets inside Russia, but employment conditions remain complex. The ability to strike Russian airfields from which planes take off to drop FAB-500s could potentially be a game-changer for the defense of Kupyansk — but it requires the kind of political coordination that the Trump administration approves with its characteristic slowness on these matters.

For now, Ukrainian defenders at Kupyansk must rely on their own resources and existing deliveries. That is not insufficient to hold — but it is potentially insufficient to retake Radkivka and stabilize the Oskil bridgehead.

The ISW as compass: what the assessments tell us

A cautious confirmation of the Russian advance

The Institute for the Study of War confirms in its assessment of June 22, 2026 that Russian forces had recently advanced in northern Kupyansk, based on a declaration from a source linked to the Russian West Forces Group indicating the capture of Radkivka. The ISW takes care to note that this declaration comes from a single source — a mark of the epistemological caution that distinguishes serious analysis from propaganda.

That caution is all the more important given that Russian milbloggers have a long tradition of exaggerating advances to sustain domestic morale. The statement on Radkivka is consistent with available geolocated imagery and with the infiltration pattern documented over months — which is why the ISW takes it seriously without elevating it to absolute certainty.

Mapping as an instrument of understanding

The real-time cartographic work carried out by organizations like the ISW or Deep State Map is indispensable for tracking the evolution of a war where front lines shift by a few hundred meters per week. For Radkivka, geolocating combat footage published on June 20 and 22 confirmed that Russian forces were operating inside the village — information that neither the Ukrainian nor the Russian command had communicated directly.

This transparency forced by geolocated imagery transforms the war into a near-real-time documented spectacle, unprecedented in military history. For supporters of Ukraine, it is an accountability tool: when a village falls, everyone sees it. There is no longer any space for denial.

Radkivka after the capture: what comes next?

Consolidate or push toward Kupyansk?

Once Radkivka is taken, Russian forces theoretically have two options: consolidate their position in the village and use it as a base for further infiltration operations toward the center of Kupyansk, or attempt an immediate push south to cut Ukrainian lines. The first option is more likely in the short term — Russian forces need to stabilize the village before using it as a foothold.

Historically in this conflict, captures of small villages like Radkivka are rarely followed by spectacular advances within 48 hours. Ukrainian counterattacks are systematic and well documented. The question is whether Ukraine has the human reserves and materiel needed to launch an effective counterattack on Radkivka without weakening other front sectors.

The Oskil bridgehead: tenable or not?

The fundamental question remains the long-term viability of the Ukrainian bridgehead east of the Oskil. If Russian forces manage to compress the corridor enough to make rotations and resupply impossible, the Ukrainian units holding that bridgehead will be forced to withdraw to the right bank. That scenario is not imminent, but it is no longer purely theoretical.

In May 2026, Colonel Trehubov declared that the bridgehead was holding despite difficult operational conditions. A month later, the Russian capture of Radkivka shows that those difficulties have only increased. Ukrainian resistance has withstood far more intense Russian offensives — but every centimeter lost at Radkivka brings the front closer to the banks of the Oskil.

FAB-500 guided munitions: the weapon reshaping tactical balances

The glide bomb as a Russian force multiplier

The FAB-500 glide bomb — a Soviet-era 500 kg aerial bomb converted into a guided munition by adding a wing and navigation kit — has become one of the most feared weapons by Ukrainian defenders on the Kharkiv front. Dropped by an Su-34 from a safe altitude and standoff distance beyond the range of Ukrainian MANPADS, it can destroy light fortifications and defensive positions with improving accuracy. Its unit cost is low compared to cruise missiles — and Russia now produces them by the hundreds each month.

On the Kupyansk axis, FAB-500s have played a critical role in weakening Ukrainian defensive positions before ground assaults. Reinforced buildings used as firing positions, buried logistics nodes, observation posts — anything that resists small arms and drones can be pulverized by a FAB-500. This asymmetry between Russian air strike power and Ukrainian ground defensive capabilities is one of the most persistent challenges of the war in 2026.

The Ukrainian response — anti-drone and air defense warfare

Ukraine's response to the FAB-500 threat is twofold. On one hand, improving short- and medium-range air defense systems to intercept Su-34s before they reach their release points — systems like NASAMS and IRIS-T, though never in sufficient numbers. On the other, degrading Russian airfields themselves — striking runways, fuel depots, and hangars housing Su-34s hundreds of kilometers inside Russian territory. This second response — deep strikes on Russian airfields — represents the most promising strategy but also the one most dependent on the long-range weapons allies are willing to deliver.

On the Kupyansk axis specifically, Ukrainian defenses have been reinforced with electronic jamming systems targeting data links on Russian observation drones — reducing their precision and their ability to guide FAB-500 strikes. This invisible electronic warfare, waged in parallel with ground combat, is a rarely covered but strategically crucial aspect of the battle for Kupyansk.

Conclusion: Kupyansk holds, but for how long?

A resistance whose cost must be acknowledged

Ukrainian resistance in the Kupyansk direction is real, documented, and worthy of deep admiration. Ukrainian forces have held this line against a numerically superior army equipped with FAB-500 glide bombs, drones, and an attrition logic the Kremlin is willing to sustain for years. Holding Kupyansk in June 2026, despite the loss of Radkivka, is itself a tactical victory within the frame of a war of attrition.

But that victory will only last if it is sustained by a continuous flow of munitions, counter-drone defense systems, and replacement personnel for units exhausted by months of intense combat. Western support is not a luxury for Kupyansk — it is the precondition for the survival of the Oskil bridgehead.

The future of a city that refuses to fall twice

Liberated in September 2022 during the great Ukrainian counteroffensive, Kupyansk carries the memory of what it lived through under Russian occupation. Its residents — those who have not fled — and its defenders know what a second fall would mean. That knowledge is, paradoxically, a military resource: it feeds a resistance that no ISW report can quantify.

Radkivka has fallen. Kupyansk holds. And between those two realities lies the daily lives of men and women who, every morning, choose to keep defending what they consider their home. This column belongs to them.

By Maxime Marquette, columnist

Columnist's transparency note

Who I am and what I am not

I am a columnist-analyst specializing in armed conflicts and geopolitics. I have no formal military training, I am not in the field at Kupyansk, and I have no direct contact with the Ukrainian or Russian command. My analysis rests exclusively on open sources — ISW reports, wire dispatches, verified press articles, and geolocated images published in the days preceding this article.

My editorial position is pro-Ukrainian and I own it: I believe that Ukrainian resistance against imperialist aggression deserves to be supported, and I say so plainly rather than feigning a neutrality that would itself be a form of taking sides. The facts I cite are real and verifiable. The opinions I express in italicized passages are my own.

My biases and my limits

I do not have access to actual casualty data for either side — this information is classified or deliberately obscured. The figures on territorial advances and recaptures I cite come from the ISW, which works with geolocated sources but cannot confirm everything in real time. It is possible that the actual situation on the ground at Radkivka differs from what the reports available at the time of writing described. War changes every hour.

I am cautious about Russian casualty figures: Ukrainian estimates tend toward optimism, and official Russian figures are notoriously understated. I prefer to describe behavioral patterns and tactical dynamics rather than cite numbers that will be contested within 24 hours.

Sources

Primary sources

ISW — Russian Offensive Campaign Assessment, June 22, 2026 — June 23, 2026

RBC Ukraine — Russia pushes to expand control east of Ukraine's Sumy region — June 26, 2026

Ukrainska Pravda — Battlefield sees 241 clashes over past day – Ukraine's General Staff — June 28, 2026

Secondary sources

ISW — Russian Offensive Campaign Assessment, June 20, 2026 — June 20, 2026

Ukrinform — Russia's plan in Kupiansk fails, but fighting on left bank of Oskil River continues — Trehubov — May 12, 2026

Kyiv Independent — With a web of drones and infiltrating infantry, Russian troops overrun Kupiansk — October 28, 2025

ISW — Russian Offensive Campaign Assessment, April 23, 2026 — April 23, 2026