Toplines

Ukrainian forces have successfully contested the initiative at both the strategic and operational levels starting in late 2025 and persisting throughout 2026 for the first time since the August 2024 Kursk Offensive. Ukrainian forces have held Russian forces to near-zero net gains since March 2026, and have conducted successful counterattacks in the Kupyansk, Oleksandrivka, and now Lyman directions.[1] Ukrainian counterattacks defeated Russian efforts to push into Dnipropetrovsk Oblast, regained lost ground in and around Kupyansk and have defeated subsequent Russian efforts to regain it, and now have destroyed a significant Russian salient that threatened the northern flank of Slovyansk and the entire Donetsk Oblast Fortress Belt. Russian forces have made limited but significant gains in and around Kostyantynivka and east of Slovyansk and Kramatorsk but are fighting to maintain momentum in these areas and elsewhere along the front line. The situation remains dynamic, and Russian commanders are reportedly pressing Russian President Vladimir Putin for a massive mobilization likely aimed at restoring their ability to seize and hold the initiative. It remains unclear how such a mobilization, if Putin actually orders it, will change the theater dynamics in the face of Ukraine’s current advantages in both tactical and operational drone operations and drone-infantry integration.

Ukrainian successes in eliminating the Russian salient north of Lyman over the past several months have disrupted the Russian military command’s plans to conduct a wide encirclement of the Fortress Belt in Donetsk Oblast from the Lyman and Dobropillya areas. Russian forces have been advancing toward Slovyansk, Kramatorsk, and Druzhkivka from the east and Kostyantynivka and Druzhkivka from the south while also trying to encircle the entire Fortress Belt from the north and southwest. Russian forces on the southern flank of the Fortress Belt have been trying to seize Dobropillya and advance from the Pokrovsk-Dobropillya sector northward to the area west of Druzhkivka and Kramatorsk, while Russian forces on the northern flank of the Fortress Belt similarly have been trying to seize Lyman, cross the Siverskyi Donets River, and advance west-southwest to the area west of Slovyansk. The Russian military command aimed for these two prongs to eventually encircle the entire Fortress Belt and the Ukrainian forces defending the cities. Ukrainian forces have eliminated the Russian salient north of Lyman in recent months and have long defended against Russian efforts to seize Lyman itself, however, disrupting this two-pronged encirclement effort.

The Russian military command will likely need to reassess its campaign designs for the southern and northern flanks of the Fortress Belt given the elimination of its salient north of Lyman and particularly if Ukrainian forces are able to fully push Russian forces back to the Zherebets River and use the canalizing terrain to create a stable defensive line. Elements of Russia’s 25th Combined Arms Army (CAA, Central Military District [CMD]) have been engaged in the effort to seize Lyman, and elements of the 20th CAA (Moscow Military District [MMD]) have been primarily focused on advancing north of Lyman, although the exact seam between the two formations’ areas of responsibility (AoRs) is unclear.[2] It is also unclear how much damage to these two formations Ukrainian forces have inflicted in the course of their months-long counterattack. The Russian military command may redeploy surviving elements of these two armies away from the Lyman area to other areas of the front if it assesses that Russian forces will be unable to resume their efforts to encircle Slovyansk or the Fortress Belt from the north and if it is confident that it can prevent Ukrainian forces from making further advances with a reduced force presence in the area. It is unclear if the Russian military command will also adjust the objective for the forces fighting, largely without success, in the Dobropillya area now that Ukrainian forces have essentially eliminated the northern half of the encirclement effort.

The Russian military command may alternatively double down on efforts to seize Lyman, possibly with some forces that had been attacking within the former salient north of Lyman, in order to try to recreate the northern prong of the envisioned encirclement. Russian forces have failed to seize Lyman since Fall 2022, however, and have had to resort to infiltration tactics in and near the town in 2026 due to Ukrainian fortifications and drone-based defenses. Russian forces are unlikely to be able to leverage reinforcements to conduct successful larger-scale infantry or mechanized assaults in the foreseeable future, however, following this dramatic setback.

Many Russian milbloggers are acknowledging that Ukrainian forces have largely eliminated the Russian salient north of Lyman and that fighting is mainly ongoing along the Zherebets River in the area. Russian milbloggers claimed on September 9 through 11 that Ukrainian forces had effectively cut the Russian salient north of Lyman and pushed Russian forces to the Zherebets River.[3] One milblogger claimed on September 11 and 12 that Ukrainian forces forded the river.[4] Ukraine’s Strategic Communications Center amplified this milblogger claim on September 12, but Ukrainian officials have not publicly confirmed Ukrainian advances in the area as of this writing.[5] One prominent milblogger noted that Ukrainian forces have been counterattacking in the area for months and complained that the Russian military command did not pay enough attention to the area during that time.[6]

Russian milbloggers have reported in recent days that fighting was ongoing along the Zherebets River near Ivanivka (on the western bank of the river) and Terny (on the eastern bank), with one source adding that Ukrainian forces likely surrounded Russian forces in Ivanivka.[7] Russian milbloggers stated from September 9 to 12 that Ukrainian forces advanced between Novoliubivka and Katerynivka and that fighting was ongoing near Balka Zhuravka (just east of Novoliubivka on the other side of the Zherebets River), indicating that Ukrainian forces advanced to the river in the northern part of the former salient.[8] Russian milbloggers stated that fighting is ongoing near Kolodyazi (roughly two kilometers west of the river), suggesting that Ukrainian forces have not advanced to the river in the southern part of the salient yet. One Russian milblogger, who acknowledged that the Russian salient was essentially gone, claimed that fighting is still ongoing in some areas within the salient, including near Shandryholove, Stavky, Derylove, and Ridkodub.[9] Some individual Russian elements may still be operating within the former salient as Ukrainian forces continue to clear the area. The full extent of Ukrainian advances in the Lyman direction and the shape of the frontline in the area remains unclear, due to limited open-source evidence about the salient. ISW will continue to update its assessment as more open-source evidence becomes available.

Russian generals have reportedly asked Russian President Vladimir Putin for an additional 800,000 troops to sustain and likely expand Russian offensive operations in the face of enormous Russian casualty rates. Ukraine’s Main Military Intelligence Directorate (GUR) Head Lieutenant General Oleh Ivashchenko stated in an interview with The Times published on September 10 that Ukrainian intelligence suggests that Russian generals have asked Putin to mobilize an additional 800,000 troops above current recruitment levels after the September 2026 State Duma elections.[10] Ivashchenko added that Russia’s current casualty rate exceeds its daily recruitment rate, with about 60 percent of casualties being killed in action, an extraordinarily high ratio of killed to wounded when the standard ratio in modern war is 1:3.

Russia does not have the training and administrative capabilities to absorb, integrate, and train 800,000 recruits at one time, particularly if Russian authorities try to do so alongside the semi-annual conscription cycle that normally starts in October. Putin signed a law in November 2026 allowing Russian military conscription administrative processes to occur year-round in an effort to avoid the challenges the Russian military faced in 2022 when attempting to institute a large-scale involuntary reserve call-up at the same time as the semi-annual fall conscription process.[11] The law aimed to mitigate bureaucratic bottlenecks that complicated Russia’s force generation efforts during large-scale involuntary call-ups, but Ivashchenko stated that the Russian military can simultaneously absorb, including mobilizing, equipping, feeding, training, and integrating, no more than 300,000 to 500,000 recruits.[12] Russian forces are already suffering from administrative and training bottlenecks for their ground forces and drone operators at their current recruitment rate, and the mobilization of hundreds of thousands of additional recruits would almost certainly exacerbate those challenges.[13] Putin is more likely to choose a more gradual and covert mobilization due to the constraints in Russia’s training and bureaucratic capabilities and concerns about public reception than to order a sudden, massive involuntary reserve call-up like the one he ordered in 2022.[14]

The increasing Russian casualty rates and declining recruitment rate will likely force Russia to conduct some form of mobilization in the near term, but the type and scope of mobilization Putin may choose is unclear at this time. Putin and other Russian officials have repeatedly denied that Russia was preparing for mobilization in the weeks leading up to the September 18-20 State Duma elections.[15] Ivashchenko reported that Russia is currently recruiting around 1,000 to 1,200 people every day, and Ukrainian General Staff data shows that Russian forces suffered an average of 1,374 casualties per day since the beginning of July 2026.[16] Russia’s current force generation system based on volunteer recruitment continues to struggle to recruit enough soldiers to replace current losses, and it remains unclear how long Russian forces will be able to sustain their current footpace offensive tempo without some form of mobilization.[17] ISW has observed indicators that suggest that Russian authorities have been preparing multiple courses of action for conducting mobilization, allowing them to execute whichever sort of mobilization Putin might order.[18] Russia’s most likely course of action is to conduct rolling call-ups that in the short term help replace Russia’s battlefield casualties. Russia’s least likely course of action is a sudden large call-up that would allow Russian forces to temporarily flood the battlefield with poorly trained servicemembers in a short time span but would be very unpopular with the Russian population and would likely yield diminishing returns due to Russia’s existing training, administrative, and logistical constraints.

The Russian General Staff likely wants to use the additional 800,000 troops to implement its offensive plans throughout the front rather than only in Donetsk, and the scope of any potential mobilization likely depends on what operations Putin authorizes. Ukrainian officials have repeatedly reported that the Russian General Staff has made plans for additional offensive operations throughout the whole theater of war, including in the Chernihiv-Kyiv direction, very likely aiming to extend the front line and exploit Ukraine’s manpower limitations.[19] The Russian General Staff likely asked Putin for 800,000 troops to be able to execute all of its planned offensive operations, not just to support a focused deployment to priority efforts in Donetsk Oblast. The type and scope of a possible Russian mobilization will thus very likely depend on what operations Putin authorizes. Any compulsory mobilization is a personal decision for Putin and is contingent on his perception of battlefield realities and regime stability.[20]

Ukrainian President Volodymyr Zelensky continues to support a future trilateral Ukrainian-Russian-US meeting and to suggest efforts to restart peace talks with Russia. Zelensky on September 11 called for Ukraine, Russia, and the United States to move to a trilateral meeting.[21] Zelensky stated that he is willing to travel to the Group of 20 (G20) leaders’ summit in Miami in December 2026 if Russian President Vladimir Putin also attends.[22] Kremlin Spokesperson Dmitry Peskov responded that Zelensky could come to Moscow if he wants to meet with Putin.[23] Zelensky also called for Russia and Ukraine to find ways to “unblock” the Black Sea and to discuss moratoriums on long-range strikes against energy and grain infrastructure, efforts that Zelensky said could act as a starting point for peace negotiations.[24]

Ukraine’s ongoing long-range strike campaign and Western sanctions are actively preventing the Russian oil industry from recovering its processing capacity and oil exports. The International Energy Agency (IEA) reported on September 11 that it has revised its baseline outlook for Russian oil processing over the next 18 months to around four million barrels a day, a 30 percent decrease from pre-2022 levels but noted that even this latest assessment may understate the Russian refining industry’s problems.[25] The IEA reported that Ukrainian strikes caused disruptions to Russia’s oil refining system and a near halt to product exports, adding that the approach of colder weather could compound the stress on the Russian energy system. The IEA reported that Ukrainian forces are conducting more precise strikes against the refineries’ secondary-processing units that require up to eight months to repair and are using multiple drone waves against single sites that overwhelm Russia’s passive and active air defenses. The IEA assessed that international sanctions against the Russian energy industry are limiting Russia’s access to replacement equipment, complicating efforts to repair facilities that Ukrainian forces have struck. The IEA report follows Russian Central Bank Chairwoman Elvira Nabiullina’s September 11 acknowledgement that Russia’s fuel market shortages — the effects of Ukraine’s long-range strike campaign against Russian energy infrastructure — were the primary cause of Russia’s accelerated price growth over the summer and are constraining Russia’s economy.[26]

Ukraine has intensified the tempo of its refinery strike campaign and improved its targeting to cause maximum pain to the Russian oil industry. Ukraine has struck at least 26 different Russian oil refineries since the beginning of 2026, mainly targeting combined electric desalination and atmospheric and vacuum distillation units (ELOU-AVT). Crude oil desalting and distillation are essential steps in treating and separating crude oil into various fractions, such as refinery gases or naphtha, making ELOU-AVT units critical components for refinery operations that function as the heart of the facility.[27]