Will Russia capture all of Kostyantynivka by December 31, 2026?

- [2026-06-23 to 2026-07-31] Russian forces broke into Kostyantynivka beginning late June 2026; by three weeks before 2026-07-31, ISW estimated Russian forces had a presence in just 37 percent of Kostiantynivka, mostly in the form of "infiltrations" rather than firm control , with infiltration spreading further by late July. (https://www.aljazeera.com/features/2026/7/31/russia-appears-to-infiltrate-first-fortress-city-as-ukraine-changes-guard) - [2026-07-02] ISW's June 2026 assessment found Russian forces maintain a presence (either through advances or infiltrations) in 36.98 percent of Kostyantynivka and made 76.73 percent of the gains in June 2026 , but Russian forces have infiltrated into a significant part of Kostyantynivka but have not secured control over or established enduring positions in much of these areas . (https://x.com/TheStudyofWar/status/2072704350359847228) - [2026-07-31] Rate of advance was slowing: ISW estimated they were capturing 16.6sq km a day in the first half of 2025, but just 1km a day in June this year; in July, the ISW has assessed that Russia has been losing territory at a rate of 1.6sq km a day . (https://www.aljazeera.com/features/2026/7/31/russia-appears-to-infiltrate-first-fortress-city-as-ukraine-changes-guard) - [2026-09-01] ISW's end-of-August assessment: Russian forces' main territorial gains in August 2026 have been in the Fortress Belt area, Donetsk Oblast; even there, Russian forces managed to achieve only marginal tactical gains and have thus far failed to complete the seizure of Kostyantynivka . (https://www.criticalthreats.org/analysis/russian-offensive-campaign-assessment-september-1-2026) - [2026-09-19] ISW reported a Russian infiltration mission in northwestern Kostyantynivka, with a Russian-occupied building struck during what ISW assesses was a Russian infiltration mission , indicating the city remained contested rather than fully captured. (https://www.criticalthreats.org/analysis/russian-offensive-campaign-assessment-september-20-2026) - [2026-09-30] ISW's September assessment showed Russia's broader Donbas advance reversing: ISW assessed that Russian forces captured approximately 176 square kilometers but lost about 256 square kilometers in September, leaving Moscow with a net loss of roughly 81 square kilometers , driven by Ukraine's Operation Vivaldi north of the Fortress Belt. (https://kyivpost.com/post/86375) - [2026-10-01] Cumulative front-wide figures via ISW: Russian forces have lost control of 293.59 square kilometers net across the entire front since March 2026 and have only gained a presence in a total of 174.44 square kilometers when accounting for Russian infiltrations since March . (https://www.criticalthreats.org/analysis/russian-offensive-campaign-assessment-october-1-2026) - [2026-10-05/06] ISW reported Ukrainian counterattacks expanding inside the Kostyantynivka sector: Ukrainian forces are reportedly expanding the area of their counterattacks in the Kostyantynivka direction; a Kremlin-affiliated milblogger claimed Ukrainian forces reportedly began counterattacking towards Rusyn Yar in early October 2026, indicating Ukrainian forces are further expanding the area of their operations . (https://www.criticalthreats.org/analysis/russian-offensive-campaign-assessment-october-6-2026) - [2026-10-06/07] ISW's daily combat log: Russian forces continued offensive operations within and west of Kostyantynivka on October 6 and 7 but did not advance , while glide-bomb strikes continued on nearby settlements to set conditions for future assaults. (https://www.criticalthreats.org/analysis/russian-offensive-campaign-assessment-october-7-2026) - [2026-10-07] Kyiv Post/NYT summary of Operation Vivaldi notes the broader Fortress Belt (Kostyantynivka-Druzhkivka-Kramatorsk-Sloviansk) remains contested, with Ukraine "preparing a fourth phase" of its counteroffensive and Russian commanders facing internal criticism for inflated reporting; Zelensky called Vivaldi "a very successful operation" that "is not finished yet." (https://kyivpost.com/post/86375) - [2026-07-20] On-the-ground reporting: Ukrainian officials said "Up to 145 Russian troops remain in Kostiantynivka as Ukrainian forces hold defense," indicating continued contested urban fighting rather than full capture. (https://kyivindependent.com/tag/kostiantynivka/) - [2026-10-09] Ukrainian General Staff reporting (via mezha.net) described ongoing daily combat episodes around the city (Kramatorsk-direction and Toretsk-direction attacks), with Russia's objective still being to "seize control of the city in the autumn period" — confirming the city is not yet fully captured as of this date. (https://mezha.net/eng/news/autumn-offensive-near-kostiantynivka-ukrainian-defense-holds-strong/) BOTTOM LINE: As of 2026-10-09 Kostyantynivka remains a contested urban battlefield — ISW's own map and assessments show Russian infiltration/partial control (roughly a third or more of the built-up area at peak in mid-2026) but not full capture, and the broader Fortress Belt offensive has stalled or reversed since September 2026 due to Ukraine's Operation Vivaldi and expanding Ukrainian counterattacks in the Kostyantynivka sector itself, making a full ISW-map capture of the entire municipality by 2026-12-31 look currently unlikely on the trend of events. NOT FOUND: An exact, current ISW percentage-of-Kostyantynivka-controlled figure for early October 2026 (last precise ISW percentage found was 36.98% as of early July 2026); a direct current screenshot/description of the ISW storymap's shading for Kostyantynivka as of October 2026; any DeepStateMap-specific percentage for Kostyantynivka as of October 2026.

- [2026-10-07] As of the most recent ISW assessment, Russian forces continued offensive operations within and west of Kostyantynivka on October 6 and 7 but did not advance. This indicates the front inside the city has stalled in early October 2026. Source: criticalthreats.org/analysis/russian-offensive-campaign-assessment-october-7-2026 - [2026-09-01] ISW's percentage-of-settlement tracker showed Russian forces maintain a presence (either through advances or infiltrations) in 72.23 percent of Kostyantynivka and have failed to completely seize the settlement, even after months of increased infiltrations and urban fighting. Source: criticalthreats.org/analysis/russian-offensive-campaign-assessment-september-1-2026 - [2026-07-02] Earlier in the campaign, ISW assessed Russian presence at a much lower level: ISW has observed evidence to assess that Russian forces maintain a presence (either through advances or infiltrations) in 36.98 percent of Kostyantynivka and made 76.73 percent of the gains in June 2026. This shows a roughly 35-percentage-point jump from ~37% to ~72% over two months (June–August), followed by stalling in September–October — the kind of nonlinear, then-plateauing pattern typical of this campaign. - [2026-07-03/04] Russia prematurely claimed full capture mid-campaign, a recurring pattern: Russian chief of the General Staff Valery Gerasimov claimed on 18 December that Russia controls 50 percent of Kostiantynivka (while ISW assessed only ~5%), and later Russia's Defense Ministry announced full capture on 3 July 2026, which Ukraine immediately denied, with Zelensky calling it "just another Russian lie." Such premature/disputed claims have occurred repeatedly and did not correspond to ISW map confirmation. Source: en.wikipedia.org/wiki/Battle_of_Kostiantynivka - [2026-09-09] For the reference class of comparable "fortress belt" and other heavily fortified Donbas cities, CNN reported: It took Russian forces nine months of fighting to seize the nearby city of Bakhmut and nearly two years to take Pokrovsk, another supply hub. It also noted ISW has calculated that at their current pace, Russian forces would not take over Donetsk until 2032 — if they can seize it at all. Source: CNN (Sept 9, 2026) - [2026-09-09] On attrition/pace context: Russia advanced or infiltrated into about 124 square kilometers (47.8 square miles) of Ukraine's territory in August, roughly a quarter of the amount of terrain it seized in the same month last year, according to ISW. This signals a general slowdown in Russian offensive tempo region-wide, consistent with the Kostyantynivka plateau. - [2025-10-25 to present] Base-rate timeline: the battle for this specific city has already lasted 25 October 2025 – present (10 months, 4 weeks and 2 days) without full capture as of the fetch date, already exceeding the 9-month Bakhmut precedent while still short of the ~22-month Pokrovsk precedent. - [2026-04-14] Regional analysts flagged that the broader Sloviansk-Kramatorsk "fortress belt" (of which Kostyantynivka is the southernmost node) is a far larger and costlier objective than prior urban battles: The area of urban and industrial developments in the four largest cities of the Sloviansk-Kramatorsk agglomeration is more than four times the size of Bakhmut and more than seven times the size of Pokrovsk. Source: ua.news (April 2026) - [2026-10-06] Recent reporting indicates a reversal of momentum rather than continued Russian advance: Ukrainian forces are reportedly expanding the area of their counterattacks in the Kostyantynivka direction. Source: criticalthreats.org/analysis/russian-offensive-campaign-assessment-october-6-2026 - [2026-10-04] ISW also reported a Russian reorganization of forces around Kostyantynivka (new 84th Motorized Rifle Division), suggesting Russia is still reinforcing for an eventual full seizure rather than having achieved it. The newly-formed 84th Motorized Rifle Division is one of the primary fighting forces in Kostyantynivka (Russia's priority effort) . Source: criticalthreats.org/analysis/russian-offensive-campaign-assessment-october-4-2026 BOTTOM LINE: The base rate from the two most comparable precedents (Bakhmut ~9 months, Pokrovsk ~20-22 months) and the city's own trajectory (ISW's tracked "presence" metric jumped from ~37% in June to ~72% by September 2026 but then stalled through early October with reported Ukrainian counterattacks) suggests full capture is plausible on a multi-month horizon but far from assured by Dec 31, 2026; comparable "near-complete but contested" sieges (e.g., Pokrovsk, Chasiv Yar) have historically taken additional months beyond the point where Russia first claimed capture, and ISW's own extrapolation implies a dramatically slower overall Donetsk conquest pace than earlier 2025 rates. NOT FOUND: An explicit current (October 2026) ISW numeric percentage-of-control figure for Kostyantynivka newer than the September 1 (72.23%) reading; any formal probabilistic forecast or betting-market historical track record specific to this settlement; DeepStateMap's current percentage figure.

YES means: the ISW map (or, if unavailable, DeepStateMap, or a negotiated settlement establishing actual Russian control) shows the entire municipality of Kostyantynivka, Donetsk Oblast, shaded as Russian-controlled/advanced terrain, with that shading persisting through a full ISW update cycle, at some point between now and December 31, 2026. - [2026-10-08] ISW's own key takeaways for October 8 state plainly that Russian forces recently advanced in Kostyantynivka and in western Zaporizhia Oblast , showing that even amid a front-wide Ukrainian counteroffensive, Kostyantynivka remains one of the few sectors where Russia is still registering forward progress on ISW's own map. (understandingwar.org via dailykos.com/stories/2026/10/8/800109677/community/1688) - [2026-10-04] ISW reports Russia has stood up a dedicated division-level formation for the city: the newly-formed 84th Motorized Rifle Division is one of the primary fighting forces in Kostyantynivka (Russia's priority effort) and, previously as a brigade, was heavily staffed and supplied, featuring at least two motorized rifle regiments and several separate battalions operating under it , indicating Moscow is reinforcing rather than deprioritizing the assault. (criticalthreats.org/analysis/russian-offensive-campaign-assessment-october-4-2026) - [2026-10-05] Meduza's battlefield explainer, summarizing the state of play amid Trump-mediated negotiations, asserts as established fact that the Russian army captured Pokrovsk and Siversk by early 2026 and Kostiantynivka that summer , showing at least one credible independent outlet already treating Kostiantynivka's fall as a settled matter distinct from the contested-city framing in ISW's daily logs — a gap that, if it narrows, points toward eventual map confirmation. (meduza.io, Oct 5 2026) - [2026-07-03/04] Russia's Defense Ministry and Gerasimov formally announced full capture to Putin, with Peskov declaring "Kostyantynivka has been completely taken. The city is now entirely under our control," demonstrating the Kremlin's political commitment to treating the city as a finished objective and its willingness to redirect forces northward once a "YES" framing is locked in, even if ISW disputed the claim at the time. (kurdistan24.net, Jul 4 2026) - [2026-06-17] Per Wikipedia's sourced battle timeline, Russian units already The Battle of Kostiantynivka is an ongoing military engagement had by mid-June reached the Kryvyi Torets river after seizing the Metallurgical Plant in central Kostiantynivka, with Ukrainian soldiers telling the BBC the city had become "a grey zone" — showing Russian forces have repeatedly penetrated to the city center, a prerequisite for eventual full-map capture. (en.wikipedia.org/wiki/Battle_of_Kostiantynivka) - [2026-08-23] Zelensky stated that Russian forces had suffered 267,000 casualties along the entire front since the beginning of the year, including 155,000 killed, and that 70 to 80 percent of all Russian losses occurred in the Kostyantynivka direction , underscoring that Moscow has concentrated the bulk of its 2026 offensive manpower and political capital specifically on this city, a mechanism consistent with continued prioritization through year-end. (en.wikipedia.org/wiki/Battle_of_Kostiantynivka) - [2026-10-01] Putin publicly framed the Donbas campaign as accelerating, asserting Ukraine and Europe "believe they'll be able to hold Donbas for only a year and a half to two years" while Russian forces "will capture it much sooner," signaling continued top-level political pressure to complete fortress-belt objectives, of which Kostyantynivka is the southernmost and most advanced node. (meduza.io, Oct 5 2026, citing Putin's Valdai remarks) - [2026-10-08] Despite the broader Operation Vivaldi reversal, the Ukrainian General Staff's own October 8 operational update shows the Kostiantynivka sector remains the single most heavily contested axis in Donetsk Oblast that day, with the Defence Forces repelled 11 enemy assaults: in the vicinity of the settlement of Kostiantynivka and in the direction of Kindrativka, Novoselivka, Toretsk and Stepiv — the highest assault count of any named sector in that day's log, confirming Russia has not let up its tempo specifically here even as it pulls back elsewhere. (mezha.net via dailykos.com, Oct 8-9 2026 data) - [Resolution-mechanism path] Separately from battlefield shading, the market's own rules provide a second, faster route to YES: Russian forces recently advanced in Kostyantynivka combined with the rules' explicit allowance that Russian milbloggers are expressing concerns that Ukraine's Operation Vivaldi... may also hinder Russian plans to assault the northern Fortress Belt cities frontally — i.e., even a stalemate elsewhere does not preclude a negotiated-settlement resolution to YES if ongoing Trump-mediated talks (referenced in the Oct 5 Meduza piece) produce a deal ceding actual control of the city, independent of ISW shading. BOTTOM LINE: The strongest case for YES rests on (1) ISW's own October 8 acknowledgment of a fresh Russian advance inside the city even as the wider front reverses, (2) Russia's continued reinforcement with a new division-level formation and the war's heaviest casualty concentration specifically in this sector, and (3) at least one credible outlet (Meduza) already describing Kostyantynivka as captured "that summer," suggesting the on-the-ground reality may be closer to full Russian control than ISW's percentage-of-presence framing implies — plus a non-map path to YES via a negotiated settlement amid active Trump-mediated talks. NOT FOUND: A specific ISW map percentage or screenshot for Kostyantynivka dated after September 1, 2026 (72.23%); any DeepStateMap numeric figure for the city in October 2026; confirmation of what the Meduza "captured that summer" line is based on versus a loose rhetorical gloss, since the same article's detailed sector-by-sector breakdown does not separately confirm full Kostyantynivka capture.

YES means: Russia achieves ISW-map shading (Assessed Russian-Controlled Terrain or Assessed Russian Advances) covering the entirety of Kostyantynivka's municipal boundary, with that shading persisting through the next full ISW update cycle, by December 31, 2026, 11:59 PM ET (or Russia obtains actual control via negotiated settlement). This dimension argues for NO — i.e., that full capture will NOT be achieved/confirmed by the deadline. - [2026-10-01] ISW's own October 1 assessment stated Russian forces continued operations within, west, and northwest of Kostyantynivka on September 30–October 1 but explicitly "did not advance," and separately noted that Operation Vivaldi "disrupted the Russian military command's plans to conduct a wide encirclement of the Fortress Belt from the Lyman and Dobropillya areas" — undercutting the broader operational plan that was meant to seal the city's fate. (criticalthreats.org/analysis/russian-offensive-campaign-assessment-october-1-2026) - [2026-10-06] ISW reported that rather than Russia closing the remaining gap, "Ukrainian forces are reportedly expanding the area of their counterattacks in the Kostyantynivka direction," with a Kremlin-affiliated milblogger confirming Ukrainian counterattacks toward Rusyn Yar in early October 2026. (criticalthreats.org/analysis/russian-offensive-campaign-assessment-october-6-2026) - [2026-10-07] ISW's October 7 daily log again recorded no progress on this axis: Russian forces continued offensive operations "within, west of, and northwest of Kostyantynivka on September 30 and October 1 but did not advance" — a pattern of stalling repeated across multiple consecutive daily cycles rather than a single data point. (criticalthreats.org/analysis/russian-offensive-campaign-assessment-october-7-2026) - [2026-07-03/04] Russia's Defense Ministry prematurely declared Kostyantynivka's capture on July 3, 2026, which was immediately disputed; CNN's investigation concluded the claim exposed "the persistence of the Kremlin's forces and the devastating casualties they will tolerate to obtain even the smallest of goals" rather than an actual completed capture — illustrating that premature "Yes-looking" claims have already failed to hold up once under this exact market's resolution logic. (cnn.com/2026/07/16/europe/russia-ukraine-kostyantynivka-capture-claim-intl) - [2026-07-05] A market-commentary piece on this very contract documented that odds spiked to 89% on the July claim/denial cycle, explicitly noting "the move is an event-driven spike; confirmation will hinge on ISW map updates that meet the contract's persistence criteria" — and that spike subsequently reversed as ISW never confirmed full shading, showing the persistence requirement is a real technical bar that has already defeated one "capture" narrative. (global-political-spotlight.com, 2026-07-05) - [2026-09-01] Even at peak Russian penetration, ISW's own percentage tracker showed Russian presence (advances+infiltrations combined, a looser standard than the qualifying "Advances/Controlled" layers alone) at 72.23%, with ISW stating Russia has "thus far failed to complete the seizure of Kostyantynivka" and "have failed to completely seize the settlement, even after months of increased infiltrations and urban fighting." Since infiltration-layer shading does not qualify for this market, the actual qualifying-layer percentage is almost certainly lower than 72%, leaving a substantial unresolved gap. (criticalthreats.org/analysis/russian-offensive-campaign-assessment-september-1-2026) - [2026-10-07] ISW's October 7 report emphasizes Russia is pivoting significant resources toward a massive winter strike campaign against Ukrainian energy infrastructure, stating Russia intends this "brutal Winter 2026-2027 strike campaign" to pressure Ukraine strategically — a resource allocation (missiles/drones toward civilian infrastructure rather than concentrated ground assault reinforcement) that is a competing priority to finishing Kostyantynivka's capture before year-end. (criticalthreats.org/analysis/russian-offensive-campaign-assessment-october-7-2026) - [2026-09-09] CNN's comparative analysis of ISW pace data found Russia's August 2026 gains were only about a quarter of the prior year's rate, and cited ISW's extrapolation that "ISW has calculated that at their current pace, Russian forces would not take over Donetsk until 2032 — if they can seize it at all." This region-wide deceleration directly constrains the odds of completing one specific fortress city within under three months. - [Historical pattern] Historical analogues cited for this same Fortress Belt campaign show Bakhmut took nine months and Pokrovsk took nearly two years to fall after urban infiltration began; Kostyantynivka's own "Battle of" timeline has already run from October 2025 infiltration to October 2026 without full capture, already exceeding Bakhmut's precedent and tracking toward Pokrovsk's longer timeline, with no acceleration evident in the October data. - [2026-10-08] A Kyiv Post ISW summary (dated ambiguously but describing October 8 strike activity) reports only that "Russian forces recently advanced in Kostyantynivka and in western Zaporizhia Oblast," phrasing consistent with incremental tactical gains rather than completion of the full-municipality capture needed for resolution. (kyivpost.com/post/86531) BOTTOM LINE: Every ISW daily/monthly data point from July through October 2026 shows Kostyantynivka remaining short of full capture, with the qualifying-layer percentage almost certainly still well below 100%, Russian momentum stalling or reversing in early October due to Ukraine's Operation Vivaldi and expanding counterattacks, a documented precedent of a premature "capture" claim (July 3) that failed to meet this market's persistence standard, and Russian resources increasingly diverted to a winter strike campaign — all pointing toward continued contestation rather than a confirmed, persistent full-municipality shading by December 31, 2026. NOT FOUND: A precise October 2026 ISW qualifying-layer (Controlled/Advances only, excluding infiltrations) percentage for Kostyantynivka; any DeepStateMap percentage for October 2026; confirmation of the exact publication date/content for the ambiguously dated "November 8, 2026" Kyiv Post ISW summary (likely a site dating anomaly referencing October 8 events).