Jens Asbjørn Bøgen
Analysts suggests that Russia will achieve some strategic gains, but that the losses will be significant.
During the weekend, the Institute for the Study of War (ISW) assessed that Russia had launched its Spring–Summer offensive of 2026, targeting the Ukrainian “Fortress Belt” in Donetsk Oblast.
Fast forward to today, and the Kremlin is already appearing to prepare for the campaign to fail.
In its March 23 update on the war in Ukraine, ISW cites Ukrainian Commander-in-Chief General Oleksandr Syrskyi as saying Russian forces have intensified ground attacks in the last week, confirming ISW’s assessment that the offensive has begun.
However, the Kremlin appears to be already laying the groundwork for how to explain to the Russian public why the offensive will fail.
What do we know about the offensive?
According to ISW, Ukrainian Commander-in-Chief Oleksandr Syrskyi said tens of thousands of soldiers have been deployed in grueling infantry assaults.
In just four days, more than 6,090 Russian personnel were killed or wounded, Syrskyi reported. Over the past week, total losses reached 8,710 troops.
ISW suggests that such casualty levels are difficult to sustain given Russia’s current mobilization pace. The think tank also said this could limit Moscow’s ability to maintain large-scale operations over time.
What is the “Fortress Belt”?
The term “Fortress Belt” is used to describe a heavily fortified 50-kilometer-long front made up of four large cities and a number of small towns and settlements.
For more than a decade, Ukraine has invested in reinforcing the “Fortress Belt”, establishing defense industry and defensive infrastructure in the area.
Instead, Russian forces are expected to achieve only modest tactical advances while continuing to suffer significant losses.
ISW assesses that Russian forces are unlikely to break through Ukraine’s defensive “Fortress Belt” in 2026.
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No breakthrough coming
At the same time, ISW notes Russian authorities are shaping a narrative to explain slow progress.
A Russian State Duma lawmaker said on March 23 that “losses are inevitable in any war, but Russian troops will try to reduce them by advancing slowly in the direction of Sloviansk and Kramatorsk,” Russian news outlet Lenta reported.
This messaging suggests expectations of a prolonged and costly campaign.
Russian command is reportedly preparing additional manpower for the offensive.
According to ISW, mobilized personnel stationed in Crimea are expected to be sent into combat, alongside redeployed marine and airborne units.
Sources: Institute for the Study of War (ISW), statements by Ukrainian military officials, Lenta
