Mason Clark, George Barros, Kateryna Stepanenko, and Karolina Hird
April 18, 6:30pm ET
Russian forces began a new phase of large-scale offensive operations in eastern Ukraine on April 18 likely intended to capture the entirety of Donetsk and Luhansk oblasts. Russian forces have been concentrating reinforcements—including both newly-deployed units and damaged units withdrawn from northeastern Ukraine—to the Donbas axis for several weeks. Russian forces conducted large-scale assaults focused on Rubizhne, Popasna, and Marinka with heavy artillery support on April 18 after previously conducting only localized attacks and shelling along the line of contact. Russian forces have not secured any major territorial gains as of publication.
The Russian offensive in the east is unlikely to be dramatically more successful than previous Russian offensives, but Russian forces may be able to wear down Ukrainian defenders or achieve limited gains. Russian forces did not take the operational pause that was likely necessary to reconstitute and properly integrate damaged units withdrawn from northeastern Ukraine into operations in eastern Ukraine. As we have assessed previously, Russian forces withdrawn from around Kyiv and going back to fight in Donbas have, at best, been patched up and filled out with soldiers from other damaged units, and the Russian military has few, if any, cohesive units not previously deployed to Ukraine to funnel into new operations. Frequent reports of disastrously low Russian morale and continuing logistics challenges indicate the effective combat power of Russian units in eastern Ukraine is a fraction of their on-paper strength in numbers of battalion tactical groups (BTGs). Russian forces may certainly be able to wear down Ukrainian positions in eastern Ukraine through the heavy concentration of firepower and sheer weight of numbers, but likely at a high cost. A sudden and dramatic Russian offensive success remains highly unlikely, however, and Ukrainian tactical losses would not spell the end of the campaign in eastern Ukraine, much less the war as a whole.
- Russian forces likely began large-scale offensive operations in Donetsk and Luhansk oblasts focused on Rubizhne, Popasna, and Marinka.
- Russian forces may be able to gain ground through the heavy concentration of artillery and numbers. However, Russian operations are unlikely to be dramatically more successful than previous major offensives around Kyiv. The Russian military is unlikely to have addressed the root causes—poor coordination, the inability to conduct cross-country operations, and low morale—that impeded prior offensives.
- Successful Ukrainian counterattacks southeast of Kharkiv will likely force Russian forces to divert some units intended for the Izyum offensive, but Ukrainian forces are unlikely to completely sever Russian lines of communication north of Izyum in the coming days.
- Ukrainian defenders in Mariupol continued to hold out against heavy Russian artillery and air bombardment.
Supporting Effort #1—Kharkiv and Izyum: (Russian objective: Advance southeast to support Russian operations in Luhansk Oblast; defend ground lines of communication (GLOCs) to the Izyum axis)
Ukrainian forces continued a successful counterattack (begun on April 16) southeast of Kharkiv, taking several small towns on April 17-18. Ukrainian forces reportedly seized
Bazaliivka, Lebyazhe, and Kutuzivka and claimed to capture several unspecified villages near Izyum.
This Ukrainian offensive will likely force Russian forces to divert some of the combat power intended for the stalled Izyum axis to defend against Ukrainian advances but is unlikely to threaten the Russian ground line of communication (GLOC) to Izyum in the coming days. Ukrainian forces already controlled elements of the M03 highway, preventing direct Russian movement from the outskirts of Kharkiv to Izyum. ISW has documented Russian forces, including a major Russian convoy observed by Maxar Technologies on April 8, deploying to Izyum using a GLOC extending from the main Russian logistics and communications center in Belgorod, Russia, directly southeast into Ukraine through Velykyi Burluk and Kupyansk before reaching frontline positions in Izyum. Ukrainian counterattacks would need to capture and hold Velykyi Burluk, approximately 45km from their current forward positions in Bazaliivka, to disrupt this GLOC. Ukrainian forces may be able to conduct such an advance over several days or weeks, but Russian forces east of Kharkiv are unlikely to collapse as quickly as Russian forces did during the final withdrawal from Kyiv and northeastern Ukraine.
Russian forces additionally have a secondary GLOC from Valuyki, Russia, directly south through Kupyansk to Izyum. The Ukrainian General Staff reported on April 6 that Russian forces began using the Valuyki-Kupyansk railway to reinforce Izyum, and several Russian units fighting in Izyum (including the 252nd Motor Rifle Regiment, 752nd Motor Rifle Regiment, and 237th Tank Regiment) are permanently based directly in or near Valuyki. Russian forces will be able to use this GLOC to reinforce operations around Izyum even if Ukrainian forces prove capable of capturing Velykyi Burluk in the coming days. The Ukrainian counterattack may successfully force Russian forces to redeploy some units intended for the Izyum axis but is unlikely to completely disrupt Russian lines of communication and reinforcement in the coming week.
Supporting Effort #2—Southern Axis: (Objective: Defend Kherson against Ukrainian counterattacks)
Fighting continued in Oleksandrivka, just west of Kherson, without any major territorial changes. Ukraine’s Airborne Forces command claimed the Ukrainian 80th Airborne Brigade captured several villages in the Mykolayiv direction, but ISW cannot
cannot confirm this claim
Supporting Effort #3—Sumy and Northeastern Ukraine: (Russian objective: Withdraw combat power in good order for redeployment to eastern Ukraine)
There was no significant change in this area in the past 24 hours.
Immediate items to watch
- Russian forces likely commenced large-scale offensive operations in Donbas but are unlikely to achieve a major breakthrough.
- Ukrainian counterattacks southeast of Kharkiv may divert some Russian units but are unlikely to sever Russian lines of communication in the coming days.
- Russian forces concentrating around Izyum will continue small-scale offensive operations to the southeast and southwest and may begin larger-scale offensives.
- Russia and its proxies may declare victory in the Battle of Mariupol.
- Russian forces could launch a new offensive operation from Donetsk City to the north through Avdiivka toward Kramatorsk.