Russian Offensive Campaign Assessment, December 21, 2025

Assessment as of: 8:45pm ET

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Russian forces are conducting a new cognitive warfare campaign through limited cross-border attacks across a broad part of the previously dormant northern frontline in Sumy and Kharkiv oblasts. Ukrainian authorities reported on December 20 and 21 that Russian forces entered Hrabovske, Sumy Oblast (a small rural village southeast of Sumy City along the international border) overnight on December 19 to 20, and the Russian Ministry of Defense (MoD) and other Russian sources claimed on December 20 and 21 that elements of the Russian had seized Hrabovske and Vysoke (immediately south of Hrabovske).[i] Ukrainian Armed Forces Main Communications Directorate Spokesperson Captain Dmytro Lykhovyi stated on December 21 that Ukrainian forces withdrew from several positions near Hrabovske and are working to stabilize the area.[ii] Available evidence indicates that Russian forces have likely seized Hrabovske. A source reportedly affiliated with Ukrainian military intelligence reported that Hrabovske is a contested "gray zone" that neither Russian nor Ukrainian forces currently control, however.[iii] Russian milbloggers reported that Russian forces advanced across the international border into Hrabovske under the cover of night and fog and also entered Ryasne (immediately west of Hrabovske).[iv] The Ukrainian Joint Forces Task Force acknowledged on December 21 that fighting continues for Hrabovske but rejected reports that Russian forces had entered Ryasne.[v] Russian sources credited elements of the 34th Motorized Rifle Brigade (49th Combined Arms Army [CAA], Southern Military District [SMD]) with the seizure of Hrabovske.[vi]

Russian forces also conducted a geographically separate across-border attack against another small rural border village in Kharkiv Oblast. Geolocated footage published on December 21 shows Russian infantry (about two squads totaling around 15 infantry) attacking Ukrainian positions in northern Sotnytskyi Kozachok (northwest of Kharkiv City, about 15 kilometers east of Grayvoron, Belgorod Oblast, and less than half a kilometer from the international border), and a Ukrainian drone unit operating in the border area reported that Ukrainian forces repelled the assault.[vii]

These two cross-border attacks likely intend to advance the Kremlin's cognitive warfare campaign to convince the West that the frontlines in Ukraine are collapsing, such that Ukraine should concede to all of Russia's demands. The Kremlin likely intends to portray these limited cross-border attacks against small rural border villages in long-dormant areas of the international border as part of a broad new Russian offensive to reinforce a false narrative that Ukraine’s frontline is collapsing across the theater. Russian President Vladimir Putin stated on December 17 that Russia will achieve all of its war goals militarily if it cannot do so diplomatically, including the creation and expansion of a "buffer zone" in Ukraine.[viii] Putin first proposed creating a "buffer zone" in Ukraine in June 2023 following limited Ukrainian cross-border raids into Belgorod Oblast.[ix] The Kremlin has since invoked the concept of this buffer zone multiple times to signal broader territorial demands in northern Ukraine, including Sumy and Kharkiv oblasts, likely to set conditions to later demand that Ukraine cede some or all of this territory due to Russia's alleged need for a buffer zone.[x] The Kremlin will likely seek to use these attacks in combination with existing narratives about the creation of a buffer zone in Ukraine to convince the West to push Ukraine to concede to Russia because Russia will inevitably seize these areas regardless.[xi] ISW continues to assess that the frontlines in Ukraine are not in danger of rapid collapse and that a Russian victory is not inevitable.[xii]

Russian forces have not set conditions to start a new offensive across the international border in northern Ukraine. ISW has not observed evidence that would indicate that Russian forces are preparing for or capable of conducting a significant offensive operation across the international border area into northern Ukraine. Much of the Sumy and Kharkiv Oblast border area, including near Hrabovske has been dormant since late Summer 2025.[xiii] The frontline near Sotnytskyi Kozachok has been dormant since Summer 2024.[xiv] Russian forces have been struggling to advance in the international border area north and northeast of Sumy City since late June 2025 and have deprioritized this area of the frontline.[xv] ISW has observed no evidence to suggest that Russian forces have conducted a large-scale redeployment of forces to the Northern Grouping of Forces’ area of responsibility or near Ukraine’s northern international border that could support a dedicated offensive operation. Elements of the 34th Motorized Rifle Brigade, which Russian sources credited with the seizure of Hrabovske, have been operating in the border area since at least December 2024.[xvi] Russian forces, rather, have redeployed forces and means away from Sumy Oblast since Summer 2025, including elite airborne (VDV) and naval infantry units that Russia uses to bear the brunt of offensive operations in prioritized areas of the frontline.[xvii] Russian forces most recently redeployed elements of the 76th VDV Division from the Sumy direction to the Hulyaipole direction in September 2025 and the Pokrovsk direction in November 2025, Russia's two most prioritized areas of the front.[xviii] A source reportedly affiliated with Ukrainian military intelligence assessed that Russian forces have not massed sufficient forces and means to ”overwhelm” Ukrainian forces near Hrabovske.[xix]

Russian forces notably have not prepared the battlefield in northern Sumy or Kharkiv oblasts for a major ground offensive through intermediate-range strikes against Ukrainian logistics.[xx] Russian forces have not conducted a sustained battlefield air interdiction (BAI) campaign with drones against operational and tactical rear areas along the international border in northern Sumy and Kharkiv oblasts to prepare the battlefield for ground assaults, as the Russian forces have done in the Pokrovsk and Hulyaipole directions.[xxi] These BAI campaigns are part of a new Russian campaign design that aims to set conditions for intensified ground operations by degrading Ukrainian logistics and defenses ahead of such ground operations.[xxii] The absence of such preparation of the battlefield in Sumy and Kharkiv oblasts is therefore noteworthy, as such shaping operations have become the standard Russian operational template for enabling ground operations. Ukrainian Joint Forces Task Force Spokesperson Colonel Viktor Trehubov’s stated that the Russian operations in the border area do not appear to be an effort to conduct a large-scale breakthrough or a major military operation but are a local provocation — a statement consistent with all available open-source information.[xxiii]

The Russian tactics in the assault in Sotnytskyi Kozachok are not consistent with Russian assault tactics across the theater and suggest the attack was designed to be seen. Russian forces conducted the assault into northern Sotnytskyi Kozachok with about two squads of personnel crossing the border in lines shoulder-to-shoulder with little dispersion. Such a manner of movement is inconsistent with Russian tactics, techniques, and procedures (TTPs) elsewhere in the theater that emphasize dispersion, infiltration, and movement in small groups of two to five soldiers to avoid detection and fire damage from Ukrainian drones. Russian forces have largely switched to conducting infiltration missions in teams of two to five personnel throughout the theater as the main mode of offensive maneuver, so the observation of an anomalously large group of Russian infantry conducting a frontal assault using outdated tactics near Sotnytskyi Kozachok is notable.[xxiv] It is currently unclear why Russian forces conducted this assault with a large group of personnel operating in close proximity to each other in contradiction of current Russian TTPs. Russian forces may have incorrectly assessed that they would not come under Ukrainian drone and artillery fire. The Russian command in the area may have made this decision out of incompetence, though this is likely not enough to explain this decision, given how prolific the TTPs for using small-group Russian assaults and infiltration missions have become throughout the theater. The Russian military command may have designed the attack to be highly visible to ensure that Ukrainian drone crews and Western analysts undoubtedly would observe a large group of personnel to map a new Russian effort in a remote part of Kharkiv Oblast to achieve an informational effect.

Forecast and indicators: Russian forces may seek to conduct further cross border assaults in the coming days and weeks as part of this cognitive warfare campaign to influence ongoing peace negotiations by portraying the northern front as collapsing. The Kremlin and Russian media may issue intensified statements that portray these limited assaults as part of a new Russian offensive. The appearance of new small-scale tactical attacks punctuating the northern frontline and intensified Russian informational agitation around such activity would not indicate an actual new major ground offensive, however. Such activity would indicate that the primary objective of these tactical assaults is to achieve informational effects and not seize territory as part of a broader offensive.

Counterindicators: This assessment will be invalidated, and Russian forces will be more likely to be conducting an actual new ground offensive operation in northern Ukraine if Russian forces begin a concerted BAI campaign targeting Ukraine’s tactical and operational rear to degrade Ukraine’s frontline logistics or if Russian forces redeploy or commit new forces to the Northern Grouping of Forces’ area of responsibility. Such redeployments very likely would require the Russian theater command to deprioritize the southern and eastern frontlines. Both of these counterindicators remain unobserved as of December 21.

Russian forces forcibly deported about 50 civilians from Sumy Oblast in violation of international law. Hrabovske Mayor Larysa Kremenza stated on December 20 that there had been about 50 civilians left in Hrabovske when Russian forces entered the settlement and that Russian forces forcibly deported these civilians to Russia.[xxv] Kremenza stated that there were no children among those forcibly deported, and Lykhovyi stated that most of these civilians are elderly and had previously refused to evacuate.[xxvi] Ukrainian officials indicated that they are increasing evacuation measures in Sumy Oblast border areas.[xxvii] Forced deportation refers to an occupying power deporting residents of an occupied area across de jure international borders and is illegal under the Fourth Geneva Convention.[xxviii] Russia has conducted an extensive forced deportation campaign in areas of occupied Ukraine for various purposes, including to Russify Ukrainian citizens, provide labor to industries in Russia, and undermine Ukraine's ability to reintegrate areas currently under occupation.[xxix] This campaign across all of occupied Ukraine intends to rob Ukraine of its multigenerational potential and damage Ukraine's future claims to its own people.[xxx]

Russian forces have likely seized Siversk — a town with a pre-war population of less than 11,000 — after 41 months of fighting. Ukrainian military observer Kostyantyn Mashovets reported on December 21 that Russian forces completed the seizure of Siversk, advanced to heights west and northwest of Siversk, and reached the chalk quarry west of Siversk.[xxxi] Mashovets reported that Russian forces also made tactical gains north of Svyato-Pokrovske and seized Fedorivka and Vasyukivka (all southwest of Siversk) since mid-November 2025.[xxxii] The Kremlin claimed that Russian forces seized Siversk as of December 11, and Russian President Vladimir Putin and senior Russian defense officials have since been using the seizure of the town to promote the false narrative that Ukrainian lines are collapsing and that Russian forces are capable of immediately threatening Slovyansk.[xxxiii] The Russian efforts in the Siversk direction have been extremely lengthy, especially given that Siversk has an area of about 10 square kilometers with a pre-war population of about 11,000. Russian forces took 41 months to advance roughly 12 kilometers from Lysychansk (east of Siversk) to the western administrative boundary of Siversk.[xxxiv] Ukrainian resistance significantly delayed Russian efforts on the approaches to Siversk: ISW assesses that Russian forces seized Verkhnokamyanske (about four kilometers east of Siversk) as of October 9, 2024, Bilohorivka (about 10 kilometers northeast of Siversk) as of February 23, 2025, and Serebryanka (about four kilometers northeast of Siversk) as of August 16, 2025.[xxxv] ISW first observed evidence that Russian forces entered Siversk’s town limits no later than November 18, indicating that Russian forces likely took 33 days to completely seize the town (with an area of three Central Parks) once entering it.[xxxvi] Russian forces must still advance the 30 kilometers from Siversk to Slovyansk and complete the seizure of Lyman before they can begin a direct assault on Slovyansk itself.[xxxvii] The Kremlin has been exaggerating the immediate implications of the seizure of Siversk in attempts to falsely portray Russian forces as imminently threatening the northern part of the Fortress Belt and making significant simultaneous advances across the theater, such that the frontline is imminently collapsing. Russian gains continue to be slow and grinding as they have been for the past two years.

US delegations continued separate meetings with Ukrainian and Russian delegations in Miami on December 21, as the Kremlin continues to reject making compromises to end the war. Ukrainian Defense Council Secretary Rustem Umerov reported that he and Chief of the Ukrainian General Staff Major General Andriy Hnatov conducted a third day of meetings with US negotiators in Miami on December 21.[xxxviii] Russian state media reported that the lead Russian negotiator and Russian Direct Investment Fund (RDIF) CEO Kirill Dmitriev held separate meetings with US Special Envoy to the Middle East Steve Witkoff and former Senior Advisor to the US President Jared Kushner on December 21.[xxxix] Russian Presidential Aide Yuriy Ushakov stated on December 21 that he is "confident" that European and Ukrainian proposals “do not improve” the peace proposal or “enhance the chances of achieving long-term peace.”[xl] Russian President Vladimir Putin and other Kremlin officials have repeatedly rejected the US-proposed 28-point peace plan or any plan requiring Russia to compromise on any of its original war aims.[xli] Putin notably used his December 19 Direct Line televised press conference to outline his demands for a future peace settlement — the same demands with which he launched the full-scale invasion in February 2022.[xlii]

Key Takeaways:

• Russian forces are conducting a new cognitive warfare campaign through limited cross-border attacks across a broad part of the previously dormant northern frontline in Sumy and Kharkiv oblasts.
• These two cross-border attacks likely intend to advance the Kremlin's cognitive warfare campaign to convince the West that the frontlines in Ukraine are collapsing, such that Ukraine should concede to all of Russia's demands.
• Russian forces have not set conditions to start a new offensive across the international border in northern Ukraine.
• Russian forces notably have not prepared the battlefield in northern Sumy or Kharkiv oblasts for a major ground offensive through intermediate-range strikes against Ukrainian logistics.
• The Russian tactics in the assault in Sotnytskyi Kozachok are not consistent with Russian assault tactics across the theater and suggest the attack was designed to be seen.
• Russian forces forcibly deported about 50 civilians from Sumy Oblast in violation of international law.
• Russian forces have likely seized Siversk — a town with a pre-war population of less than 11,000 — after 41 months of fighting.
• US delegations continued separate meetings with Ukrainian and Russian delegations in Miami on December 21 as the Kremlin continues to reject making compromises to end the war.
• Ukrainian forces recently advanced in the border area of Belgorod Oblast and near Pokrovsk. Russian forces recently advanced in the Slovyansk-Lyman direction, in the border areas of Sumy and Kharkiv oblasts, and near Borova and Siversk.

We do not report in detail on Russian war crimes because these activities are well-covered in Western media and do not directly affect the military operations we are assessing and forecasting. We will continue to evaluate and report on the effects of these criminal activities on the Ukrainian military and the Ukrainian population and specifically on combat in Ukrainian urban areas. We utterly condemn Russian violations of the laws of armed conflict and the Geneva Conventions and crimes against humanity even though we do not describe them in these reports.

• Ukrainian Operations in the Russian Federation
• Russian Supporting Effort – Northern Axis
• Russian Main Effort – Eastern Ukraine (comprised of three subordinate main efforts)
• Russian Subordinate Main Effort #1 – Push Ukrainian forces back from the international border with Belgorod Oblast and approach to within tube artillery range of Kharkiv City
• Russian Subordinate Main Effort #2 – Capture the remainder of Luhansk Oblast and push westward into eastern Kharkiv Oblast and encircle northern Donetsk Oblast
• Russian Subordinate Main Effort #3 – Capture the entirety of Donetsk Oblast, the claimed territory of Russia’s proxies in Donbas, and possibly advance into Dnipropetrovsk Oblast
• Russian Supporting Effort – Southern Axis
• Russian Air, Missile, and Drone Campaign
• Significant Activity in Belarus

Ukrainian Operations in the Russian Federation

Ukrainian forces recently conducted a limited cross-border attack in the Belgorod Oblast border area.

Assessed Ukrainian advances: Geolocated footage published on December 21 indicates that Ukrainian forces recently advanced across the international border into a forest area northeast of Mukhin, Belgorod Oblast (southeast of Shebekino and less than one kilometer from the international border) during a limited cross-border attack.[xliii]

Russian Supporting Effort – Northern Axis (Russian objective: Create defensible buffer zones in northern Ukraine along the international border)

Russian forces recently conducted cross-border attacks into northern Ukraine.

See topline text for recent limited Russian and Ukrainian cross-border assaults.

Assessed Russian infiltrations: Geolocated footage published on December 19 shows Russian servicemembers operating south of Oleksiivka (north of Sumy City) during what ISW assesses was a Russian infiltration mission that did not change control of terrain or the forward edge of the battle area (FEBA) at this time.[xliv]

Russian forces attacked in Kursk and Sumy oblasts, including north of Sumy City near Kindrativka; northeast of Sumy City near Varachyne; and southeast of Sumy City near Hrabovske and toward Ryasne on December 20 and 21.[xlv]

A Russian milblogger reportedly affiliated with the Russian Northern Grouping of Forces claimed that the Russian military command committed elements of the 4th Battalion of the 1st Motorized Rifle Regiment (Territorial Control) (Russian Strategic Missile Forces [RVSN] and reportedly under the operational control of the Russian Northern Grouping of Forces) to attritional assaults near Oleksiivka (north of Sumy City).[xlvi] The milblogger added that the Russian military command deployed elements of the 22nd Motorized Rifle Regiment (72nd Motorized Rifle Division, 44th Army Corps [AC], Leningrad Military District [LMD]) composed of servicemembers suffering from chronic medical conditions to the frontline near Bilovody (northeast of Sumy City).[xlvii]

Order of Battle: Drone operators of the Russian Chechen Akhmat Spetsnaz Kanada Detachment (204th Akhmat Spetsnaz Regiment) are reportedly striking Ukrainian forces near Myropillya (northeast of Sumy City).[xlviii] Artillery elements of the 106th Airborne (VDV) Division reportedly continue to strike Ukrainian forces in Sumy Oblast border areas.[xlix]

Russian Main Effort – Eastern Ukraine

Russian Subordinate Main Effort #1 – Kharkiv Oblast (Russian objective: Push Ukrainian forces back from the international border with Belgorod Oblast and approach to within tube artillery range of Kharkiv City)

Russian forces recently advanced in northern Kharkiv Oblast.

See topline for more information about Russian infiltrations in northern Kharkiv Oblast.

Russian forces attacked northwest of Kharkiv City near Sotnytskyi Kozachok and northeast of Kharkiv City near Vovchansk, Vilcha, Prylipka, and Izbytske on December 20 and 21.[l]

Order of Battle: Elements of the 2nd Battalion of the Russian 1st Motorized Rifle Regiment (Territorial Control) (Russian Strategic Missile Forces [RVSN] and reportedly under the operational control of the Russian Northern Grouping of Forces) are reportedly operating near Vovchansk.[li] Drone operators of the 136th Motorized Rifle Brigade (58th Combined Arms Army [CAA], Southern Military District [SMD]) reportedly continue to operate in the Kharkiv direction.[lii]

Russian forces attacked east of Velykyi Burluk toward Hryhorivka and southeast of Velykyi Burluk near Dvorichanske and toward Obukhivka on December 20 and 21.[liii]

Russian Subordinate Main Effort #2 – Luhansk Oblast (Russian objective: Capture the remainder of Luhansk Oblast and push westward into eastern Kharkiv Oblast and northern Donetsk Oblast)

Russian forces continued offensive operations in the Kupyansk direction on December 21 but did not advance.

Russian forces attacked east of Kupyansk near Petropavlivka and southeast of Kupyansk near Stepova Novoselivka, Kurylivka, Hlushkivka, and Pishchane on December 20 and 21.[liv]

Order of Battle: Elements of the Russian 352nd Motorized Rifle Regiment (11th Army Corps [AC], Leningrad Military District [LMD]) reportedly continue to operate in the Kupyansk direction.[lv]

Russian forces recently advanced in the Borova direction.

Assessed Russian advances: The Ukrainian General Staff published maps on December 21 acknowledging a Russian presence south of Zelenyi Hai and west of Serhiivka (both east of Borova) and Novovodyane (southeast of Borova).[lvi]

Russian forces attacked north of Borova near Novoplatonivka, northeast of Borova near Nova Kruhlyakivka and Bohuslavka, and southeast of Borova near Novoyehorivka, Olhivka, and Novovodyane, and toward Druzhelyubivka and Stepove on December 20 and 21.[lvii]

Russian forces recently advanced in the Slovyansk-Lyman direction.

Assessed Russian advances: Ukrainian military observer Kostyantyn Mashovets reported on December 21 that Russian forces currently occupy positions in southeastern Lyman.[lviii] The Ukrainian General Staff published maps on December 21 acknowledging a Russian presence north and south of Serednie, northeast of Drobysheve (both northwest of Lyman), and in eastern Novomykhailivka (north of Lyman). [lix]

Russian forces attacked near and within Lyman itself; northwest of Lyman near Serednie and toward Drobysheve and Korovii Yar; north of Lyman near Ridkodub and Stavky; northeast of Lyman near Kolodyazi; and east of Lyman near Zarichne on December 20 and 21.[lx]

Mashovets reported that Russian forces in the Lyman direction are focusing offensive operations in the area of responsibility (AoR) of the Russian 144th Motorized Rifle Division (20th Combined Arms Army [CAA], Moscow Military District [MMD]) from Shandryholove toward Yarova (both northwest of Lyman) as well as in the AoR of the 164th and 169th motorized rifle brigades (both 25th CAA, Central Military District [CMD]) from Yampil toward Ozerne (both southeast of Lyman) and southeastern Lyman.[lxi] Mashovets reported that the Russian military command is pursuing several simultaneous tactical objectives, including seizing the Yarova-Novoselivka-Drobysheve-Pryshyb area (north to northwest of Lyman) to cut Ukrainian ground lines of communication (GLOCs) into Lyman from the northwest; reach the Siverskyi Donets River near Ozerne and seize Dibrova (southeast of Lyman) to set conditions for assaults on Lyman from the southeast and east; and to support elements of the 3rd CAA (formerly 1st Luhansk People's Republic Army Corps [LNR AC], Southern Military District [SMD]) fighting on the opposite bank of the Siverskyi Donets River in the Siversk direction. Mashovets assessed that Russian forces have likely reached the Siverskyi Donets River east of Yampil and are striking Ukrainian forces operating near Zakitne and Platonivka (both northwest of Siversk).

Order of Battle: Mashovets reported that elements of the Russian 1st and 15th motorized rifle regiments (both of the 2nd Motorized Rifle Division, 1st Guards Tank Army [GTA], MMD) are operating in the Lyman direction.[lxii] Elements of the 237th Tank Regiment (3rd Motorized Rifle Division, 20th CAA, MMD) are reportedly operating in the Lyman direction.[lxiii]

Russian Subordinate Main Effort #3 – Donetsk Oblast (Russian objective: Capture the entirety of Donetsk Oblast, the claimed territory of Russia’s proxies in Donbas, and advance into Dnipropetrovsk Oblast)

Russian forces recently advanced in the Siversk direction.

See topline text for additional assessed Russian advances in the Siversk direction.

Assessed Russian advances: Ukrainian military observer Kostyantyn Mashovets reported on December 21 that Russian forces advanced to the T-0513 Siversk-Lyman highway between Lyman and Zakitne (northwest of Siversk).[lxiv]

Russian forces attacked near Siversk itself; northwest of Siversk near Yampil, Dronivka, and Zakitne; south of Siversk near Kuzmynivka; southeast of Siversk near Vyimka; and southwest of Siversk near Bondarne on December 20 and 21.[lxv]

Mashovets assessed on December 21 that the military command of the Russian 3rd Combined Arms Army (CAA, formerly 2nd Luhansk People's Republic Army Corps [LNR AC], Southern Military District [SMD]) aims to advance as far west along the southern (right) bank of the Siverskyi Donets River as possible to enable elements of the 3rd and its neighboring 20th and 25th CAAs, operating in the Slovyansk–Lyman direction, to transfer forces across the river without coming under Ukrainian fire.[lxvi] Mashovets reported that Russian forces likely outflanked Platonivka (northwest of Siversk) from the south.[lxvii]

Order of Battle: Elements of the Russian 6th and 123rd Motorized Rifle Brigade (both of the 3rd CAA) are operating near Svyato-Pokrovske.[lxviii] Artillery elements of the 88th Motorized Rifle Brigade (3rd CAA) are striking Ukrainian forces south of Riznykivka (southwest of Siversk).[lxix] Drone operators and other elements of the 169th Motorized Rifle Brigade (25th CAA, Central Military District [CMD]) reportedly continue to operate near Yampil.[lxx]

Russian forces continued offensive operations in the Kostyantynivka-Druzhkivka tactical area on December 21 but did not advance.

Assessed Ukrainian advances: Geolocated footage published on December 19 indicates that Ukrainian forces advanced north of Shcherbynivka (southeast of Kostyantynivka).[lxxi] ISW assesses that this change did not occur in the last 24 hours.

Assessed Russian infiltrations: Geolocated footage published on December 21 shows Russian forces operating northwest of Predtechyne (east of Kostyantynivka) in what ISW assesses as a Russian infiltration mission that did not change control of terrain or the forward edge of the battle area (FEBA) at this time.[lxxii]

Russian forces attacked near and within Kostyantynivka itself; north of Kostyantynivka toward Vyrolyubivka; northeast of Kostyantynivka toward Minkivka; east of Kostyantynivka near Oleksandro-Shultyne; southeast of Kostyantynivka near Pleshchiivka and Kleban-Byk; southwest of Kostyantynivka toward Stepanivka; south of Druzhkivka near Rusyn Yar; and southwest of Druzhkivka near Sofiivka on December 20 and 21.[lxxiii]

Order of Battle: Drone operators of the Russian 27th Artillery Regiment (6th Motorized Rifle Division, 3rd AC, under operational control of the Southern Grouping of Forces) and 103rd Motorized Rifle Regiment (150th Motorized Rifle Division, 8th CAA, SMD) are reportedly striking Ukrainian equipment and positions near and within Kostyantynivka.[lxxiv] Drone operators of the Smuglyanka Detachment and Rubikon Center for Advanced Unmanned Technologies are reportedly coordinating Russian Aerospace Forces [VKS] FAB guided glide bomb strikes against Ukrainian forces near Druzhkivka.[lxxv]

Russian forces continued offensive operations in the Dobropillya tactical area on December 21 but did not advance.

Russian forces attacked east of Dobropillya near Shakhove and Nove Shakhove and southeast of Dobropillya near Zapovidne on December 20 and 21.[lxxvi]

Order of Battle: Drone operators of the Russian 163rd Tank Regiment (150th Motorized Rifle Division) are reportedly striking Ukrainian positions near Toretske (east of Dobropillya).[lxxvii] Elements of the 174th Separate Reconnaissance Battalion (150th Motorized Rifle Division) and the 33rd Motorized Rifle Regiment (20th Motorized Rifle Division, 8th CAA) reportedly continue to operate in the Dobropillya direction.[lxxviii]

Ukrainian forces recently advanced in the Pokrovsk direction on December 21.

Assessed Ukrainian advances: Geolocated footage published on December 20 indicates that Ukrainian forces recently advanced along the M-30 Selydove-Pokrovsk highway in the western outskirts of Pokrovsk.[lxxix]

Assessed Russian infiltrations: Geolocated footage published on December 21 shows Russian forces operating in northwestern Myrnohrad (east of Pokrovsk) during what ISW assesses was a Russian infiltration mission that did not change the control of terrain or FEBA at this time.[lxxx]

Unconfirmed claims: Russian milbloggers claimed that Russian forces advanced along the Donetska railway west of Pokrovsk and northwest of Udachne (southwest of Pokrovsk).[lxxxi]

Refinements of area under Russian claims: Geolocated footage published on December 21 shows Ukrainian forces operating along the M-30 highway in the western outskirts of Pokrovsk — an area where Russian sources previously claimed Russian forces maintained a presence.[lxxxii]

Russian forces attacked near and within Pokrovsk itself; northwest of Pokrovsk near Hryshyne; north of Pokrovsk near Rodynske; northeast of Pokrovsk near Sukhetske; east of Pokrovsk near and within Myrnohrad; and southwest of Pokrovsk near Kotlyne, Udachne, and Molodetske on December 20 and 21.[lxxxiii]

Ukrainian 7th Rapid Reaction Corps of the Air Assault Forces commander Brigadier General Yevhen Lasiychuk reported on December 21 that Ukrainian forces have recently retaken areas on the western outskirts of Pokrovsk in local counterattacks as Russian forces have become bogged down in urban warfare within the town.[lxxxiv] Lasiychuk reported that Russian forces have lost at least 6,500 servicemembers in the Pokrovsk direction since September 1, 2025.

The Ukrainian General Staff published footage on December 21 showing Russian forces in the Pokrovsk direction targeting a small group of Ukrainian servicemembers with a swarm of about 20 first-person view (FPV) drones in quick succession.[lxxxv]

Order of Battle: Elements of the Russian 1435th Motorized Rifle Regiment (likely comprised of mobilized personnel) (reportedly of the 2nd CAA, CMD) are operating in Svitle (east of Pokrovsk).[lxxxvi] Elements of the 76th Airborne (VDV) Division and of the 506th Motorized Rifle Regiment (27th Motorized Rifle Division, 2nd CAA) are reportedly operating in Pokrovsk.[lxxxvii] Elements of the 268th Self-Propelled Artillery Regiment (27th Motorized Rifle Division) are reportedly operating in the Pokrovsk direction.[lxxxviii]

Russian forces continued offensive operations in the Novopavlivka direction on December 21 but did not make confirmed advances.

Unconfirmed claims: A Russian milblogger claimed that Russian forces advanced northwest of Novomykolaivka (northeast of Novopavlivka).[lxxxix]

Russian forces attacked near Novopavlivka itself, northeast of Novopavlivka near Novoserhiivka, and southeast of Novopavlivka near Filiya and Dachne on December 20 and 21.[xc]

Russian forces continued offensive operations in the Oleksandrivka direction on December 21 but did not advance.

Assessed Russian infiltrations: Geolocated footage published on December 20 shows Ukrainian forces striking Russian servicemembers northwest of Ivanivka (northeast of Oleksandrivka) during what ISW assesses was a Russian infiltration mission that did not change control of terrain or the FEBA at this time.[xci]

Russian forces attacked northeast of Oleksandrivka near Zelenyi Hai, Andriivka-Klevtsove, and Ivanivka; east of Oleksandrivka near Piddubne and Oleksandrohrad; southeast of Oleksandrivka near Sosnivka, Verbove, Pryvilne, and Sichneve; and south of Oleksandrivka near Vyshneve on December 20 and 21.[xcii]

Order of Battle: FPV drone operators of the Russian 36th Motorized Rifle Brigade (29th CAA, Eastern Military District [EMD]) are striking Ukrainian positions east of Vidradne (south of Oleksandrivka).[xciii]

Russian Supporting Effort – Southern Axis (Russian objective: Maintain frontline positions, secure rear areas against Ukrainian strikes, and advance within tube artillery range of Zaporizhzhia City)

Russian forces continued offensive operations in the Hulyaipole direction on December 21 but did not make confirmed advances.

Unconfirmed claims: Russian milbloggers claimed that Russian forces advanced in northwestern, central, and southwestern Hulyaipole, south of Hulyaipole, east of and in central Andriivka, and east of Zelene (both north of Hulyaipole).[xciv]

Russian forces attacked near and within Hulyaipole itself; northwest of Hulyaipole toward Ternuvate; north of Hulyaipole near Radisne, Herasymivka, Andriivka, Nove Zaporizhzhia, Dobropillya, Ostapivske, and toward Zelene, Varvarivka, Bratske, and Kosivtseve; and northeast of Hulyaipole near Zlahoda, Pryvilne, and Rybne on December 20 and 21.[xcv] Russian milbloggers claimed that Ukrainian forces counterattacked near Hulyaipole and Dobropillya.[xcvi]

Order of Battle: Drone operators of the Russian 14th Spetsnaz Brigade (Russian General Staff's Main Directorate [GRU]) are reportedly striking Ukrainian positions near Ternuvate and Rizdvyanka (northwest of Hulyaipole).[xcvii] Elements of the Russian 11th Air Force and Air Defense Army (Russian Aerospace Forces [VKS] and Eastern Military District [EMD]) are reportedly striking Ukrainian positions in Hulyaipole.[xcviii]

Russian forces continued offensive operations in western Zaporizhia Oblast on December 21 but did not advance.

Russian forces attacked west of Orikhiv near Novoandriivka, Shcherbaky, Maly Shcherbaky, Stepove, Stepnohirsk, and Prymorske on December 20 and 21.[xcix]

Order of Battle: Drone operators of the Russian 7th Airborne (VDV) Division, including its 108th VDV Regiment, are reportedly striking Ukrainian forces west of and in Prymorske.[c] Drone operators of the 4th Military Base (58th Combined Arms Army [CAA], Southern Military District [SMD]) reportedly continue to strike Ukrainian positions in the Orikhiv direction.[ci] Assault elements of the 104th VDV Division are reportedly conducting training in occupied Zaporizhia Oblast.[cii]

Russian forces continued limited ground assaults in the Kherson direction on December 21 but did not advance.

Russian forces attacked east of Kherson City near the Antonivskyi Bridge on December 20 and 21.[ciii]

Order of Battle: Drone operators of the Russian 98th VDV Division are reportedly striking cell towers in Kherson City.[civ] Elements of the BARS-33 Detachment (Russian Combat Army Reserve) are reportedly operating in occupied Kherson Oblast.[cv] Drone operators of the 331st VDV Regiment (98th VDV Division) are reportedly operating in the Kherson direction.[cvi]

Russian Air, Missile, and Drone Campaign (Russian Objective: Target Ukrainian military and civilian infrastructure in the rear and on the frontline)

Russian forces conducted a series of drone strikes against Ukraine overnight on December 20 to 21. The Ukrainian Air Force reported that Russian forces launched 97 Shahed-type, Gerbera-type, and other drones — of which about 60 were Shahed-type drones — from the directions of Kursk City; Millerovo, Rostov Oblast; Primorsko-Akhtarsk, Krasnodar Krai; and occupied Cape Chauda and Hvardiiske, Crimea.[cvii] The Ukrainian Air Force reported that Ukrainian forces downed 75 drones in northern, western, and southern Ukraine as of 0830 local time and that 19 drones struck eight locations in Ukraine. Ukrainian officials reported that Russian forces struck civilian, industrial, and port infrastructure in Rivne and Odesa oblasts.[cviii] Ukrainian President Volodymyr Zelensky reported on December 21 that Russian forces launched approximately 1,300 strike drones, 1,200 guided aerial bombs, and nine missiles against Ukraine over the past week (roughly from December 14 to 21), specifically targeting Odesa Oblast and southern Ukraine.[cix]

Significant activity in Belarus (Russian efforts to increase its military presence in Belarus and further integrate Belarus into Russian-favorable frameworks)

Russian President Vladimir Putin met with Belarusian President Alexander Lukashenko on December 21 to discuss bilateral relations and issues pertaining to the Eurasian Economic Union (EAEU).[cx]

Note: ISW does not receive any classified material from any source, uses only publicly available information, and draws extensively on Russian, Ukrainian, and Western reporting and social media as well as commercially available satellite imagery and other geospatial data as the basis for these reports. References to all sources used are provided in the endnotes of each update.