Theater at the Periphery, Attrition at the Core: Zapad-2025 and Eastern Sentry

Editor’s Note: This situational assessment is derived from the Institute for the Study of War’s update dated September 12, 2025, and complementary public reporting. It is presented to inform ComplexDiscovery’s readers—professionals across legal, cybersecurity, information governance, and intelligence sectors—of evolving military and geopolitical dynamics that shape risk, compliance, and operational planning. It is the fourth autumn of Russia’s full-scale war against Ukraine. The joint strategic exercise Zapad-2025 runs from September 12–16 and is the first Zapad iteration since the invasion, as Zapad-2023 did not take place. Publicly cited Zapad-2025 participant numbers are external estimates rather than organizer-declared totals. Poland’s closure of its border crossings with Belarus began on September 12, with no end date announced.

Background Note: ComplexDiscovery’s staff offers distinctive perspectives on the Russo-Ukrainian war and Middle Eastern conflicts, informed by their military experience on the West German, East German, and Czechoslovakian borders during the Cold War, as well as in Sinai as part of Camp David Accord compliance activities, during the timeframe of the Persian Gulf War. This firsthand regional knowledge has been further enhanced by recent staff travels to Eastern European countries, including Estonia, Finland, Latvia, Lithuania, and Poland. These visits have provided up-to-date, on-the-ground insights into the current geopolitical climate in regions directly impacted by the ongoing conflict.

Combined with cybersecurity, information governance, and eDiscovery proficiency, this multifaceted experience enables comprehensive analysis of these conflicts, including the critical impact of cyber warfare, disinformation, and digital forensics on modern military engagements. This unique background positions ComplexDiscovery to provide valuable insights for conflict-related investigations and litigation, where understanding the interplay of technology, data, and geopolitical factors is crucial.

Russo-Ukrainian Conflict Update*

Theater at the Periphery, Attrition at the Core: Zapad-2025 and Eastern Sentry

ComplexDiscovery Staff

As autumn 2025 opens, the war’s tempo is defined by a striking juxtaposition: spectacle at the periphery and attrition at the core. In Belarus and western Russia, authorities launched Zapad-2025, the Union State’s first major capstone exercise since 2021, while NATO moved in parallel to harden the Alliance’s eastern flank following Russian drone incursions into Polish airspace earlier in the week. The choreography—scripted maneuvers on one side, a vigilant defensive screen on the other—sets the strategic weather pattern over a frontline that remains governed by close-quarters engagements, incremental advances, and relentless drone and artillery interdiction.

Zapad-2025 is formally scheduled for September 12–16 across sites in Russia and Belarus, including the Vitebsk, Minsk, and Grodno oblasts in Belarus, as well as activity in the Baltic and Barents Seas, and combined-arms training at the 227th Training Ground near Barysaw. Belarusian officials describe a two-stage construct: an initial emphasis on air and ground defense followed by operations to clear territory and conduct counteroffensives. After weeks of sharper signaling—at times evoking nuclear-related scenarios—Minsk and Moscow have softened their public posture, recasting the exercise as defensive and moving “deep inside” Belarus. External assessments place total participation near 30,000 across both countries, with roughly 8,000 in Belarus (about 2,000 Russian and 6,000 Belarusian personnel). While far smaller than the 2021 iteration and following the cancellation of Zapad-2023, the drill remains politically weighty as a live test of interoperability, logistics, and command-and-control under wartime constraints.

NATO’s answer to the September 9–10 drone violation of Polish airspace arrived on September 12 with the activation of Eastern Sentry—an allied posture designed to integrate air and ground-based defenses, accelerate information sharing, and fast-track counter-drone capabilities. Early participating allies include Denmark, France, the United Kingdom, and Germany. The immediate focus is on Poland, with the explicit acknowledgment that implications extend beyond any single border. In tandem, Warsaw instituted a border closure with Belarus beginning September 12, citing heightened risk associated with Zapad-2025 and the preceding airspace incident. Belarusian outlets reported traffic surges and diversions to neighboring crossings; Minsk and Moscow accused Warsaw of overreaction and emphasized invitations to international observers. Whatever the rhetoric, the net effect is clear: risk-mitigation on NATO’s flank is tightening in step with Union State signaling.

On the economic front, Russia’s stabilization effort and Western sanctions pressure intersected in telling ways. The Central Bank of Russia lowered its key interest rate to 17 percent—its third cut since June—while acknowledging elevated inflation expectations and deteriorating external trade conditions. In parallel, partners tightened restrictions. The United Kingdom introduced a large tranche of new designations targeting procurement networks and the shadow fleet moving Russian crude. Japan expanded its listings and aligned its crude oil price cap to $47.60 per barrel, mirrored by New Zealand’s adjustment and penalties. The European Union extended its Russia sanctions framework. Together, these measures aim to compress the financial headroom that underwrites Moscow’s war effort, particularly through maritime exports and enabling logistics.

Kinetic activity beyond the front line continued to shape the week’s strategic narrative. Ukrainian security services conducted long-range drone strikes against energy infrastructure in Russia’s Leningrad and Smolensk oblasts on the night of September 11–12. Reported targets included the Primorsk Baltic oil terminal—Russia’s largest on the Baltic—and pumping stations on the Baltic Pipeline System that feed Ust-Luga. Regional authorities in Leningrad Oblast reported multiple interceptions and fires, with emergency services responding at a port facility and a pumping site. In Smolensk Oblast, widely shared visuals showed fires at a Lukoil depot in Kardymovo. Moscow’s Ministry of Defense claimed extensive downings over both regions; Ukrainian sources framed the strikes as part of a continuing effort to degrade Russia’s oil export infrastructure and impose costs at depth.

Russia, for its part, continued its air, missile, and drone campaign against Ukraine. The Ukrainian Air Force reported that approximately forty drones—more than twenty of them Shahed-type systems—were launched from multiple directions overnight, with air defenses downing or suppressing thirty-three. Strikes resulted in at least three civilian deaths and five injuries, with damage reported in Sumy City and in Kharkiv and Mykolaiv oblasts. The pattern remains familiar: sustained, multi-axis pressure intended to tax air defenses and generate episodic disruption, offset by significant attrition of inbound systems and rapid restoration and remediation efforts across targeted locales.

On the ground, the fighting remained intense yet localized. In the northern theater around Sumy, Russian forces attacked near Kindrativka, Oleksiivka, Varachyne, Yablunivka, and Yunakivka, but Ukrainian units reported a decrease in offensive tempo attributed to successful defensive measures. Assault compositions have shifted toward small four-person teams operating without armored vehicles, supported by basic unmanned ground vehicles that shuttle ammunition and medical supplies under fire. Prominent pro-Russian commentators criticized the new Northern Grouping of Forces commander and described disorganized retreats by elements near Kindrativka and Yunakivka, including a reported refusal to authorize a withdrawal request by elements of the 810th Separate Naval Infantry Brigade—claims that, if accurate, highlight command friction in this sector.

In northern Kharkiv Oblast, Russian forces continued attacks near Vovchansk and Synelnykove, with an unconfirmed claim of gains in western Vovchansk. Activity persisted in the Velykyi Burluk direction around Ambarne and Odradne. In the Kupyansk sector, assaults continued north, northeast, and southeast of the city, while a Ukrainian drone regiment commander emphasized that Kyiv maintains full control of Kupyansk. Russian forces reportedly attempted river crossings on improvised craft and infiltrations in civilian dress for propaganda purposes, underscoring the information-operations overlay on tactical actions.

Further south, Russia registered recent gains in the Lyman direction, with independently verified visuals published by open-source analysts showing advances northwest of Stavky. Ukrainian reporting described Russian infiltration tactics, including concealment in basements and quadcopter resupply of small detachments, and intense contestation over landmarks such as the church in Zarichne. In the Siversk sector, Ukrainian forces repelled a reinforced platoon-sized mechanized assault and noted Russian efforts to establish a foothold before autumn rains reduce mobility. In the Kostyantynivka–Druzhkivka tactical area, Russian forces recently advanced southeast of Sofiivka and east of Volodymyrivka, while other claims—so far unconfirmed—extend those gains further. A prominent Russian milblogger asserted that a first-person-view drone struck central Kramatorsk for the first time, consistent with a standoff strike envelope now reaching roughly twenty to thirty kilometers from the front.

The Pokrovsk axis remained heavily contested, with Russian assaults reported across a wide arc around the city and intensified pressure south of Pokrovsk. Russian sources articulated an intent to seize Rodynske and Krasnyi Lyman—the small settlement northeast of Pokrovsk, not the city of Lyman—to encircle Myrnohrad and attack its northern outskirts. Notably, Ukrainian forces achieved a localized but meaningful success in the Novopavlivka direction by liberating Filiya, reversing Russian gains assessed in late August, and improving the security of nearby supply tracks.

In the Velykomykhailivka direction, Russian forces advanced in eastern Ternove, with credible indications that Ternove and Komyshuvakha are likely under Russian control. East and west of Orikhiv, Russian attacks continued without confirmed breakthroughs; reporting from the Stepnohirsk–Prymorske area described a contested gray zone and airborne units clearing the Kollektivni Sady area, including the FPV destruction of a road bridge to complicate Ukrainian movement. Limited Russian attacks persisted in the Kherson direction without advance. Across these sectors, the through-line remains constant: both sides are pressing for tactically advantageous ground before autumn weather degrades mobility, while drones, loitering munitions, mines, and counter-battery duels set the pace of attrition.

For ComplexDiscovery’s community, the implications are direct. Zapad-2025 and NATO’s Eastern Sentry highlight the growing integration of military, technological, and legal-economic instruments in the conflict’s prosecution and containment. Cross-border airspace incidents, sanctions calibration, and long-range strikes on energy infrastructure now impact cyber threat exposure, incident response preparedness, cross-border data movement, supply chain assurance, and evidentiary standards for future accountability processes. The pattern that opened this assessment—theater at the periphery, attrition at the core—therefore provides the essential framework for understanding current risk dynamics. As scripted drills conclude and lessons are absorbed into operational practice, will the theater at the periphery meaningfully reshape the war’s balance, or will the attritional core decide the course of this fourth autumn?

Assessed Control of Terrain Map for September 12, 2025 (Kharkiv)

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* Sourced and shared with permission from the Institute for the Study of War (ISW).

Additional Reading

• From Dissent to OSINT? Understanding, Influencing, and Protecting Roles, Reputation, and Revenue
• Data Embassies: Sovereignty, Security, and Continuity for Nation-States

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