How Ukraine’s Critical ‘Fortress Belt’ Could Be Lost Under Putin’s Demands

Kremlin demands for Ukraine to cede territory in the Donetsk region to Russia for a ceasefire could hand Moscow a big battlefield advantage, the Institute for the Study of War (ISW) has said.

Ahead of a summit between President Donald Trump and Vladimir Putin in Alaska next week, reports cited by the ISW say the fate of Ukrainian territory Russia partially occupies could be given up to Moscow in exchange for an end to the fighting.

The Washington, D.C, think tank said that surrendering strategically vital unoccupied territory in the Donetsk region could force Ukraine to abandon its main defensive line in the region known as the “fortress belt.”

Newsweek has contacted the Ukrainian Defense Ministry for comment.

Why It Matters

The fortress belt is made up of four large cities and other towns that run north to south over 30 miles along Donetsk’s H-20 Kostyantynivka-Slovyansk highway and has proved to be an obstacle to Russian territorial ambitions since 2014.

Trump has said peace talks in Alaska on August 15 would likely discussing “some swapping of territories.”

Ukraine’s president, Volodymyr Zelensky, has repeatedly rejected this move, citing the Ukrainian Constitution but the ISW report outlines its battlefield implications.

What To Know

Kremlin officials want Ukraine to cede Crimea and all of Donetsk and Luhansk oblasts that comprise the Donbas region, as well as freeze other parts of the front line in a ceasefire, Bloomberg, citing unnamed sources, said, according to the ISW.

Such a move would include Kyiv withdrawing troops from Ukrainian-controlled territory in the Donbas, which Moscow has tried and failed to capture.

This would hand Russia control of the main fortified defensive line in the Donetsk region which Ukraine has spent over a decade reinforcing.

But handing over the whole region for a ceasefire with no final peace settlement would allow Moscow’s forces to renew their attacks on much more favorable terms without any further struggle for the territory where they are trying to envelop from the southwest, the ISW said.

Russian forces failed to envelop all of Ukraine’s fortress belt in 2022, and such an operation would likely take years and involve high personnel and equipment losses, the think tank said.

Ceding Ukrainian-held parts of the Donetsk region would allow Moscow to avoid this complication and let its forces go to the border of the region, which is significantly less defensible than the current line.

This would force Ukraine to built fortifications to be built along the Kharkiv and Dnipropetrovsk border areas, the terrain of which is poorly suited to act as a defensive line, the ISW said.

The think tank said Russian forces will almost certainly violate any future ceasefire or peace agreement and renew military aggression unless a peace agreement includes robust monitoring mechanisms and security guarantees for Ukraine,

This highlights the battlefield as well as diplomatic stakes in the coming summit between Trump and Putin on August 15.

In an article for the Substack Faridaily, Russia watchers Farida Rustamova and Margarita Liutova said their sources in Moscow said the U.S. does not understand that Putin cannot pause the war without something he can sell to the Russian public as a win.

In comments sent to Newsweek, John Herbst, from the Atlantic Council’s Eurasia Center said that territorial concessions to Moscow are “front-loaded, but the critical things that Moscow must accept will be handled in subsequent peace negotiations.”

These include Moscow’s response to the U.S. and NATO arming of Ukraine, as well as the potential stationing of European peacekeepers in Ukraine.

But a temporary ceasefire should not be confused for a lasting peace, Herbst added as Putin’s goal to get political control of Ukraine.

What People Are Saying

The Institute for the Study of War said on Friday: “The surrender of the rest of Donetsk Oblast as the prerequisite of a ceasefire with no commitment to a final peace settlement ending the war would position Russian forces extremely well to renew their attacks on much more favorable terms.

“Conceding such a demand would force Ukraine to abandon its “fortress belt,” the main fortified defensive line in Donetsk Oblast since 2014 — with no guarantee that fighting will not resume.”

John Herbst, senior director of the Atlantic Council’s Eurasia Center said the ceasefire terms “reflect what Putin is willing to accept and do now. It says nothing about what he will do in the future.”

What Happens Next

On Saturday, Zelensky has reiterated Ukraine’s unwillingness to cede territory for peace, which will add to the anticipation over whether next Friday’s summit in Alaska between Putin and Trump can yield a breakthrough.