Pushing Ukraine to give up Donbas is strategic error — ISW

ISW highlighted a Financial Times article stating that U.S. security guarantees for Ukraine are allegedly contingent on Kyiv agreeing to a peace settlement — one that may likely include transferring all of Donbas (both Luhansk and Donetsk oblasts, including territories now controlled by Ukraine) to Russia.

Two FT sources said the United States signaled it will be willing to provide Ukraine with additional weapons to strengthen its army in peacetime if Kyiv agrees to withdraw its forces from the entirety of Donbas.

The sources also claimed that the proposed U.S. security guarantees will include a commitment that “reflects” the spirit of NATO’s Article 5, along with a promise of a coordinated military response in the event of a “sustained” Russian attack on postwar Ukraine. One source suggested that the guarantees might be too vague for Ukraine, while at the same time too broad for Russia.

[While the White House has denied that the United States is making these demands of Ukraine, Reuters published similar report on Jan. 28, stating that Ukraine will need to sign a peace deal with Russia before receiving U.S. security guarantees.]

In this context, ISW analysts described pressure on Ukraine to make territorial concessions — particularly over areas Russia is unlikely to seize quickly or easily by military means — as a strategic error.

ISW continues to assess that Russia will need to expend significant resources, time, and manpower to capture the remainder of Donbas. Even assuming Russian forces could maintain the rate of advance seen in late November 2025, they will still be unlikely to seize all of Donetsk Oblast before August 2027, the Institute noted.

The analysts also recalled that Russia’s rate of advance slowed in late December 2025 and early January 2026 — likely in part due to severe weather conditions. As a result, Russia’s efforts to fully occupy Donetsk Oblast could take even longer than previously estimated.

Meanwhile, a withdrawal of Ukrainian forces from the parts of Donetsk Oblast that remain under Kyiv’s control will give Russian troops more favorable positions for future offensives toward southwestern and central Ukraine after a pause to regenerate forces.

To effectively deter this renewed Russian aggression, ISW highlighted that Ukraine will need a strong military and reliable Western security guarantees. Russian officials, however, have repeatedly rejected this idea.

On Jan. 26, Russian Foreign Intelligence Service chief Sergey Naryshkin said that the European “Coalition of the Willing” was advancing peace terms that were “absolutely unacceptable” to Russia — likely referring to coalition efforts to deploy deterrence forces in postwar Ukraine.

On Jan. 27, Russian State Duma Defense Committee deputy chairman Aleksey Zhuravlyov openly rejected the idea of deploying NATO-country troops in Ukraine after the war.

As ISW concluded, the Kremlin is therefore unlikely to accept any settlement that includes meaningful security guarantees for Ukraine. These rejections and Moscow’s consistent disregard for the negotiating process indicate that Russia remains committed to Vladimir Putin’s “theory of victory” — the belief that Russia can outlast Ukraine until Kyiv’s ability to fight is exhausted and Western willingness to support Ukraine fades.