REPORT: KOSTIANTYNIVKA — 53 RUSSIANS FALL EVERY DAY FOR A CITY THEY DO NOT HAVE

Introduction: the bloodiest front of June 2026

A ratio that says everything about the state of the conflict

On June 23, 2026, from the Kostiantynivka front, Yuriy Madyar — deputy commander of the Ukrainian 19th Army Corps — made public a figure that summarizes the war in this city in a way no speech can match: Russian forces are suffering approximately 53 casualties per day in the Kostiantynivka direction. Ukrainian forces on that same axis: approximately three. This ratio of 17.6 to one, reported by the Institute for the Study of War (ISW) in its assessment of June 23, is not propaganda rhetoric. It is operational data issued by a ground commander, cross-referenced with the independent analyses of the ISW. It says, without ornamentation, what the Russian offensive costs on that axis.

To those 53 daily casualties is added a logistical detail that Madyar also revealed: Russian forces must march 20 to 30 kilometers to approach Kostiantynivka, because Ukraine is striking the surrounding areas with enough intensity to make any mechanized movement risky. Every Russian soldier who enters the combat zone does so after a march of several hours under the constant threat of Ukrainian drones. This is not a progression — it is an organized hemorrhage.

What Kostiantynivka represents in the geography of the conflict

Kostiantynivka is an industrial city in eastern Ukraine, in Donetsk oblast. In peacetime, it had approximately 70,000 inhabitants. It is part of the fortress belt — that arc of fortified cities constituting Ukraine's defensive depth in the Donbas. For Russia, taking it would mean a potential breakthrough toward Druzhkivka and ultimately toward Kramatorsk and Sloviansk. For Ukraine, holding it is a matter of time and human resources — but also of strategic honor. Russian forces first entered it in October 2025. By June 2026, according to ISW, they control or have infiltrated less than 13% of the city. Eight months. Thirteen percent. Fifty-three dead per day.

The reality of the front line — what the data reveals

Infiltrations without doctrinal control

The ISW insisted in several June 2026 assessments on a fundamental operational distinction: the infiltration of Russian forces into Kostiantynivka does not constitute actual control of terrain in the military sense. Infiltrating means that small groups of Russian soldiers have managed to penetrate certain buildings and blocks of the city — often at night, via roundabout routes to avoid consolidated Ukrainian positions. Controlling means holding stable positions, securing supply routes, preventing enemy counter-attacks, and maintaining command coherence in a delimited area. These conditions are not met.

A Russian milblogger — those semi-official commentators who operate on the margins of state media — himself admitted, according to ISW, that Russian forces are struggling to resupply their positions in the northern part of the city and are relying on drone drops. Soldiers resupplied only by drones inside a building in enemy territory are not soldiers controlling a city — they are soldiers surviving in a precarious pocket. This situation is documented, cross-referenced, and independently confirmed by the ISW's geolocated assessments.

Ukrainian counter-offensives to the south

Madyar confirmed on June 23, 2026 that Ukrainian forces had cleared areas to the south of Kostiantynivka, leaving a "minimum" number of Russian soldiers in the area, and that operations are underway to push Russian soldiers back from the center and west of the city. ISW independently confirmed that Ukrainian forces had regained some positions — a reality that the Russian "imminent capture" narrative systematically ignores. Madyar also rejected Russian claims of a Ukrainian encirclement: there is no encirclement. There are far more Ukrainian soldiers than Russian soldiers in the city.

These combined elements — counter-offensive to the south, position recovery, denial of encirclement — paint the portrait of a combat zone where Ukraine maintains its local operational initiative despite a tactical situation that is deteriorating in certain sectors. This is not a stable, comfortable front. It is building-by-building, street-by-street warfare, where every block changes hands in a lethal ballet. But it is a war that Ukraine is conducting actively — not enduring passively.

The soldiers — what numbers alone do not say

53 Russian casualties — the human beings behind the statistics

Allow a necessary digression. The 53 Russian casualties per day at Kostiantynivka — a figure that includes killed, seriously wounded, and prisoners under standard military operational terminology — represent 53 broken human trajectories every day. These are not abstract entities in an ISW assessment. They are men sent into a warzone city by a command that knows — or should know — the cost of what it orders. After an article on this war, someone wrote to us that they thought of their brother, forcibly mobilized in Russia, from whom the family had received no information in months. Let us call him Alexei. He is twenty-four years old. He thought he would be home in three months. Perhaps right now he is marching those 25 kilometers under drones toward Kostiantynivka. This is not an invention — it is a reality that repeats itself hundreds of times a day in Putin's Russia.

Ukraine also pays a price. Three casualties per day on this axis — three is a smaller number, but every life lost is total and irreplaceable. Behind each of Madyar's figures are Ukrainian families waiting for news that does not come, or that comes in the most painful words there are. The war at Kostiantynivka is not abstract — it is daily, physical, irreversible. The statistics allow it to be understood strategically. They are not enough to understand it humanly.

The deployment of Russian reinforcements

According to ISW, since March 2026, Russia has considerably intensified its offensive operations toward Kostiantynivka, after abandoning its attempts toward Sloviansk to the north — where the deployed mechanized brigades did not have the breakthrough capacity. Kostiantynivka became the main priority of Russia's spring-summer offensive by default as much as by choice. The Sloviansk attack units were redirected. Reinforcements were sent. According to ISW, by June 2026, approximately 80% of the attacking units originally sent to Kostiantynivka had been reconstituted after the losses sustained. This high regeneration rate says two things: the losses were massive, and Moscow is determined to maintain pressure regardless.

But reconstituting units to 80% does not mean reconstituting them to the same quality. New recruits, even in sufficient numbers, do not replace accumulated combat experience. The most experienced Russian soldiers are those who have survived the longest — and these are often the first in infiltration units that absorb the heaviest losses. The 80% reconstitution conceals a qualitative degradation that percentages do not capture.

Russian logistics — a chain under maximum pressure

25 kilometers on foot under drones

The detail provided by Madyar — that Russian forces must march 20 to 30 kilometers to approach Kostiantynivka — deserves elaboration. This march does not take place on a secured road. It takes place in an environment where Ukrainian drones patrol roads, intersections, and crossing points. It takes place with heavy equipment — ammunition, food, medical supplies. It takes place knowing that any concentration of soldiers becomes a target. And it takes place to reach a city where the Russians arrive already exhausted before facing Ukrainian resistance inside.

Ukraine's intermediate-range strike campaign — which targets Russian logistical lines behind the front lines — is directly responsible for this situation. By destroying fuel depots, supply vehicles, and transit points in occupied areas, Ukraine forces Russian forces to fall back on more primitive supply modes: marching on foot, drone delivery, manual carrying. This logistical regression is a silent Ukrainian victory that does not make headlines but determines Russian offensive capability on a daily basis.

Fuel as a strategic weapon

The suspension of civilian fuel sales in occupied Crimea — a decision announced by Sergei Aksyonov, Moscow's appointed governor — illustrates the growing pressure on Russian supplies. Ukrainian strikes on Crimea's energy infrastructure forced the occupation authorities to ration available fuel in priority for military needs. When an occupying army begins cutting fuel to civilians to feed its own vehicles, it is a sign of a logistical chain in difficulty. And all military camps — including forces on the Kostiantynivka axis — depend on that same disrupted logistical chain.

Russia, the world's third-largest oil producer, faced local fuel shortages in its own territories in June 2026 due to Ukrainian strikes on its refineries. The Moscow Kapotnya refinery — which supplies approximately 40% of Moscow's oil market — will be out of service for at least six months according to industrial sources cited by Reuters. Deputy Prime Minister Novak publicly acknowledged an oil production decline at the St. Petersburg Economic Forum. Ukraine's energy campaign is producing real effects on the Russian economy and, by extension, on military logistics.

The information war around Kostiantynivka

AI videos to fabricate nonexistent victories

The ISW documented in its June 23, 2026 assessment something qualitatively new in the Russian cognitive war around Kostiantynivka: the promotion of artificial intelligence-generated videos presenting fictitious Russian successes on the ground. RBC-Ukraine had reported in June 2026 that experts had identified the potential use of AI to create falsified visual content about operations in the city. This content is distributed via pro-Russian milblogger networks on Telegram, then picked up by state media, then cited in official statements — creating an information cascade in which an artificial image ends up feeding a presidential speech.

This technological escalation in the information war deserves attention. In 2022, Russian disinformation relied primarily on unsubstantiated claims and rudimentary photographic reconstructions. In 2026, it relies on AI-generated visual content that untrained eyes cannot distinguish from real imagery. The sophistication of the tool does not change its nature: it is a lie dressed as evidence. But it is a lie that becomes harder to contest in the speed of the digital news cycle.

The inflated estimates of the Russian Ministry of Defense

The Russian Ministry of Defense continues to publish hyper-tactical data about Kostiantynivka — allegedly captured intersections, allegedly controlled buildings, allegedly secured zones. These micro-details serve to create an impression of steady progress without ever providing a coherent operational picture. According to independent experts cited by RBC-Ukraine, estimates of Russian soldiers present in the city range from 93 to 153 saboteurs — well below the 250 to 300 soldiers advanced by Russian statements. The gap between estimates is itself an indicator: Russian command systematically overstates its committed forces to minimize the humiliation of a catastrophic casualty ratio.

In February 2026, ISW had already documented that the head of the Russian general staff's main operational directorate, Sergei Rudskoy, had claimed Russian forces had captured approximately 900 square kilometers and 42 localities since the beginning of 2026. ISW's independent calculations gave 572 confirmed square kilometers and 19 localities. The Russian commander overstated his own results by 57% on localities. When generals lie to their own hierarchy, the quality of operational decisions degrades accordingly.

Civilian victims — the invisible price of urban battle

A city emptied of its inhabitants

Kostiantynivka had approximately 70,000 inhabitants before the war. By June 2026, virtually all civilians had fled. Those who remain — often elderly people unable or unwilling to leave — live in basements and shelters, under bombs and drones. Russian strikes targeted civilian infrastructure: water systems, electricity, residential buildings. The physical destruction of a city in which both sides are fighting is total and irreversible. Every conquered building is potentially a destroyed building. Every liberated street is potentially a street in ruins.

This picture of systematic destruction repeats itself in all the cities of the fortress belt that have been touched by combat. Bakhmut, Avdiivka, Marinka — cities that existed, that had histories, markets, schools — have been reduced to expanses of concrete and metal. Kostiantynivka follows that same path as the battle intensifies. What Ukraine defends is also the right of these cities to exist after the war — not just coordinates on a strategic map.

The UN report on civilian casualties — May 2026

A UN human rights mission cited by PBS documented that in May 2026, 274 civilians were killed and 1,763 wounded in Russian strikes in Ukraine — the highest monthly figure since April 2022. The majority of these victims were in cities far from the front, targeted by Russian drone and missile strikes deliberately targeting residential areas. These figures are added to military casualties — but they represent a different reality: families who had not chosen to be at the front, but whom the front came to find in their homes.

The battle for Kostiantynivka produces documented military casualties. It also produces less-documented civilian casualties, in a city where evacuations are not always possible and where the line between combat zone and residential area has long ceased to exist. Every strike — Russian or Ukrainian in exchanges — in an urban environment carries the risk of hitting non-combatants. That is the reality of urban warfare, and it is incompatible with the triumphant victory narratives Moscow broadcasts.

Comparing casualties in the broader 2026 context

Russian advance rate in free fall

To understand what 53 Russian casualties per day at Kostiantynivka means in the broader context, one must look at ISW's global figures. In 2025, Russian forces advanced while losing on average 83 soldiers per square kilometer gained. In 2026, their overall advance rate dropped to 7.87% of what it was in 2025 over the same period. Russian forces gain less, at the same human cost — or more. The attrition calculus becomes increasingly unfavorable for Moscow with each passing week.

On the Kostiantynivka direction specifically, projecting the casualty ratio from June 23, 2026 over a monthly period: 53 Russian casualties per day × 30 days = 1,590 Russian casualties per month on that axis alone. Against 90 Ukrainian casualties over the same period. These figures, applied across a front of several hundred kilometers, project a Russian army bleeding at an unsustainable pace over the long term, even if the Russian mobilization machine continues producing soldiers in quantity.

The human effort of Russian mobilization

Russia has put in place since 2022 a partial mobilization, voluntary recruitment under strong economic pressure, and an enlistment bonus system that attracts men in precarious situations into the army's ranks. These mechanisms produce soldiers in numbers but not necessarily in quality. The recruits sent to Kostiantynivka are not all hardened professionals — some are men with minimal military training, sent to fill losses in a city their government presents as "practically taken."

According to publicly available data, Russia recruits approximately 25,000 to 30,000 new soldiers per month since the partial mobilization of September 2022. This incoming flow is largely consumed by losses sustained. The Russian army is not growing significantly — it maintains its force level by replacing losses with new recruits, with a progressive deterioration of the average soldier quality. This reality is incompatible with the narrative of an army on a victorious offensive.

ISW data from June 2026 — an assessment that leaves no room for ambiguity

Five key points from the June 23 assessment

The ISW assessment of June 23, 2026 concerning Kostiantynivka can be summarized in five verified points: 1) The Ukrainian tactical situation is deteriorating in certain sectors. 2) Russian claims of imminent capture are false. 3) Russian forces are suffering approximately 53 casualties per day against 3 on the Ukrainian side on that axis. 4) Ukrainian forces are regaining positions and conducting operations south of the city. 5) Russian cognitive warfare efforts, including AI videos, aim to saturate the informational space with false success narratives. These five points, combined, give a complex picture — neither Ukrainian collapse nor comfortable status quo — which is the reality of war in June 2026.

ISW also noted that Russian forces are unable to consolidate their positions after infiltration and will need more personnel to convert these infiltrations into usable front lines. This need for additional forces runs directly into the logistical constraints documented by Madyar — 25 kilometers under strikes, drone resupply in advanced positions. The mechanism that should enable Kostiantynivka's capture runs up against its own capacity limits at every step.

The June 2026 assessment in continuity with previous assessments

ISW had already assessed in June 2026 that Russian forces would likely make tactical gains at Kostiantynivka over the summer, but would remain incapable of a rapid operational breakthrough against the fortress belt as a whole. This distinction between tactical and operational levels is fundamental: Russia can gain meters, blocks, floors of a building. It cannot win the fortress belt war under the same conditions. These two levels of analysis coexist — and the confusion between them is exactly what Russian propaganda cultivates.

Over the first six months of 2026, ISW calculated that Russian forces had gained control of or infiltrated 40.64 square kilometers between December 2025 and May 2026 — compared to 515.84 square kilometers over the same period in 2025. The difference is abyssal and documented. This is not a Russian victory in progress. It is a progressive and measurable degradation of Russian military performance.

The Kostiantynivka front in the diplomatic context

The direct link between territorial gains and negotiating pressure

The battle of Kostiantynivka is not unfolding in a political vacuum. It unfolds simultaneously with diplomatic talks around a possible ceasefire, the G7 in Évian in June 2026, and Putin's declarations about his "will for peace." The connection is explicit: every Russian gain at Kostiantynivka — even marginal, even fragmentary — is used as evidence of the "battlefield realities" Putin invokes to demand that negotiations account for his current territorial positions.

That is why Ukrainian resistance at Kostiantynivka has a direct diplomatic dimension. Holding the front, absorbing Russian losses at a ratio of 17.6 to one, counter-attacking to the south, refusing encirclement — all of this sends a message to the negotiating tables: Ukraine holds, the front is not collapsing, and "battlefield realities" do not justify Russian maximum demands. Madyar's war of numbers is also a diplomatic war.

What a ceasefire would mean for Kostiantynivka

A ceasefire along the current front line — as proposed by Ukraine's UN representative Andrii Melnyk, who declared on June 23, 2026 that it is "already a significant compromise" — would freeze current positions around Kostiantynivka. This scenario has its own complications: the city would be a potentially shared combat zone between Ukrainian and Russian forces, with Russian infiltration positions inside. A freeze of front lines is not necessarily a return to normalcy for Kostiantynivka — it is perhaps a prolongation of chaos in another form.

What Kyiv wants is not only a ceasefire — it is a ceasefire paired with security guarantees that would prevent the resumption of the Russian offensive once forces have been reconstituted. That is the lesson of Minsk: a ceasefire without an enforcement mechanism is a pause before the next offensive. And the next offensive, under the current disarmament conditions the Istanbul protocols would propose, would unfold in conditions even less favorable for Ukraine.

Lessons from Kostiantynivka for military doctrine

Urban warfare in 2026 — drones, infiltration, and attrition

Kostiantynivka in June 2026 offers a lesson in contemporary military doctrine: modern urban warfare plays out simultaneously on three levels. The first level is physical — soldiers in buildings, ground positions, direct lines of fire. The second level is logistical — who can resupply their positions, maintain their forces, replace their losses. The third level is informational — who controls the narrative about the state of combat. Russia temporarily dominates the first level in certain sectors. It is progressively losing the second level. It attempts to dominate the third level through disinformation, including AI videos.

Ukraine dominates the second level — its logistical lines to Kostiantynivka remain open, its soldiers do not march 25 kilometers under drones to reach their positions. It also dominates the third level in Western information spaces, thanks to the credibility of Madyar's data and ISW analyses. The first level — building-by-building combat — is more balanced, with mixed control zones and active counter-offensives on both sides. This distribution of dominance explains why Russia bleeds at 53 against 3 without progressing significantly.

The role of drones in transforming the battlefield

NATO Secretary General Mark Rutte declared in June 2026 that Ukraine has become the world's number one in drone and counter-drone technology. This statement is not marketing — it is based on documented operational realities. The 200 to 300 Ukrainian drones launched daily toward targets in Russian territory, according to data reported by Business Insider, represent an unprecedented deep-strike capability for a country of Ukraine's size.

At Kostiantynivka, Ukrainian drones fulfill several functions simultaneously: real-time reconnaissance, strikes on Russian supply lines, interception of approaching soldiers, counter-battery against artillery positions. It is this drone saturation of the tactical space that forces Russians to march 25 kilometers on foot rather than using military vehicles. Ukrainian drone technology is a force multiplier that partly explains the asymmetric casualty ratio — the Russians are fighting in an environment where their movements are visible, tracked, and targeted in near-real time.

The truth about Kostiantynivka in five figures

The data that refutes the Russian narrative

To summarize the reality of Kostiantynivka on June 23, 2026 in verifiable data: 53 — Russian casualties per day on that axis according to Madyar. 3 — Ukrainian casualties per day on that same axis. 20 to 30 — kilometers Russian reinforcements must march under strikes to approach. 12.69% — maximum share of the city where Russians maintain a presence, according to ISW. 8 months — duration of Russian presence in the city since October 2025. These five figures, all sourced and verifiable, draw a picture that formally contradicts Putin's claims of June 23, 2026 about an "imminent" capture.

To these five figures is added a fact documented by ISW: Ukrainian forces have regained some positions and are conducting active operations to recover the center and west of the city. That is not the description of a defense in its death throes. It is the description of active, costly, painful resistance — but active. And this distinction between passive defense and active resistance is crucial to understanding what is really happening at Kostiantynivka.

What Ukraine is defending and why it matters

Kostiantynivka is not merely a point on a military map. It is a Ukrainian city. It was an industrial center, a place to live, a community hub for tens of thousands of people. The resistance at Kostiantynivka is also resistance to the idea that these cities can be erased, taken, and transformed into occupied territories at Moscow's will. It is resistance with all its contradictions — destructive to the city itself in the short term, but defending the principle that a nation has the right to its territorial integrity. That principle is larger than Kostiantynivka. That is why it is worth defending, even at this price.

Comparing sources and cross-validation

Convergence of data between independent sources

An important element of credibility in this report is the convergence of data between independent sources. Madyar — a Ukrainian operational source — reports 53 against 3. ISW — an independent American think tank — confirms the Ukrainian counter-offensives to the south and the falsity of Russian imminent capture claims. A Russian milblogger — an informal pro-Russian source — admits resupply difficulties. Global data on Russia's 2026 advance rate — 7.87% of 2025 — confirms the offensive's deceleration. This convergence between sources of different nature and interest increases the reliability of the overall picture.

The main divergence remains between official Russian communications — which claim imminent progress — and the totality of available independent data. This divergence is not analytical nuance. It is the difference between propaganda and reality. And in a conflict where information is a strategic weapon, distinguishing the two clearly is an act of columnist journalistic responsibility.

What we do not know with certainty

Honesty requires signaling what this report cannot claim with certainty. The figures of 53 against 3 are operational data provided by a Ukrainian commander — they are credible and consistent with other sources, but they cannot be independently audited with absolute certainty. The estimates of 93 to 153 Russian saboteurs in the city are independent analyses, not physical counts. The exact state of every city sector, building by building, is not publicly accessible. What we know is sufficiently substantiated for the conclusions drawn — but the uncertainty inherent in any combat zone must be named.

Provisional conclusion: this front in June 2026

A city that holds, an army that bleeds, a narrative that lies

As of June 23, 2026, the situation at Kostiantynivka can be summarized as follows: Ukraine holds a city Russia has been claiming to be on the verge of taking for eight months, inflicting a casualty ratio of 17.6 to one on the attacker, while maintaining active counter-offensive operations. Russia infiltrates positions in the city without consolidating them, bleeding at 53 casualties per day, resupplying its advanced soldiers by drones for lack of secured access routes, and compensating for its real operational failures through a disinformation campaign that includes AI-generated videos.

This portrait is not flattering to Moscow — but it is not Ukrainian triumphalism either. The tactical situation is deteriorating in certain sectors according to ISW. Ukrainian casualties, while three times fewer than Russian casualties, are nonetheless real and painful. The city is being destroyed. The remaining civilians are suffering. This honest picture — limited Russian gains, active Ukrainian resistance, human cost on both sides — is more useful than any victory or defeat narrative.

Conclusion: numbers do not lie

A tally that speaks for itself

On June 23, 2026, Vladimir Putin said that Russian forces are "practically reaching" Kostiantynivka. That same day, Yuriy Madyar reported 53 Russian casualties against 3 Ukrainian, Russian reinforcements marching 25 kilometers under drones, and active Ukrainian counter-offensives to the south of the city. ISW confirmed that claims of imminent capture are false, that Ukrainian forces are regaining positions, and that Russian cognitive warfare efforts include AI videos of fictitious victories.

Madyar's numbers do not lie. The reality of 25 kilometers of marching under drones does not lie. 8 months for 13% of a city does not lie. Kostiantynivka holds. Ukraine pays to hold it. And Putin continues to describe a world that exists only in his speeches and in the videos generated by his artificial intelligence.

Final conclusion: what Kostiantynivka says about the war

A revealing battle

Kostiantynivka in June 2026 is a mirror of this war in its totality: a Russian offensive that consumes human resources at an unsustainable rate for marginal gains; a Ukrainian defense that maintains its coherence through a combination of courage, drone technology, and Western support; an information war in which Russia fabricates victories that its soldiers cannot achieve on the ground. This mirror says something essential: this war is not being won by Russia. It is being slowly lost, at 53 casualties per day, in a city Putin has been calling "practically taken" since the leaves fell in autumn 2025.

And all the while, Zelensky holds the line. Ukrainian soldiers hold their positions. And the truth, quantified by Madyar on that June 23, 2026, circulates in the world despite the Kremlin's AI videos. That may be Ukraine's most underestimated victory in this war: maintaining a space of truth in an environment of organized lying. Not spectacular. But indispensable.

Signed Maxime Marquette, columnist

Columnist's transparency box

Editorial positioning

This report is written from an assumed pro-Ukraine posture, considering Ukrainian resistance at Kostiantynivka as legitimate and strategically justified. This posture did not lead to the invention of facts or the exaggeration of available data. The figures cited — casualty ratio, percentage of city controlled, Russian marching distance — all come from identified sources. Uncertainties have been flagged.

Methodology and sources

Primary operational data comes from the ISW assessment of June 23, 2026, which documents Madyar's statements, analyses of the Kostiantynivka situation, and assessments of Russian cognitive warfare efforts. Data on Russian territorial gains (40.64 sq km in 2026 vs. 515.84 sq km in 2025) comes from June 2026 ISW assessments. The city percentage (12.69%) comes from ISW cited by UA.NEWS (June 2026). Civilian casualty data (274 killed, 1,763 wounded in May 2026) comes from the UN mission report cited by PBS. The duration of Russian engagement (since October 2025) is documented by multiple ISW sources. No data was invented.

Nature of the analysis

This text is an analytical report that compiles operational data to paint a factual picture of the battle of Kostiantynivka as of June 23, 2026. It integrates an editorial judgment on source reliability (Madyar and ISW data versus official Russian statements) that flows from an analysis of internal coherence and convergence between independent sources. The Alexei framing is honestly presented as a rhetorical device to embody a statistical reality — not as direct testimony.

Sources

Primary sources

ISW — Russian Offensive Campaign Assessment, June 23, 2026 (Madyar data, infiltrations, Ukrainian counter-offensives)

PBS — Ukraine and Russia exchange deadly strikes, at least 1 child killed in Sumy — June 22, 2026

RBC-Ukraine — Russia falsifies Kostiantynivka capture, ISW reveals the reality — June 16, 2026

Secondary sources

UA.NEWS — Russia failed to take Kostiantynivka before May — ISW — June 11, 2026

ISW — Russian Offensive Campaign Assessment, June 21, 2026

RBC-Ukraine — Russia's "big wins" are fake, according to ISW — February 21, 2026