Ukraine replaces its defence minister and army chief within a week as the battle for Kostiantynivka intensifies

Ukraine has installed new political leadership at its defence ministry and new military leadership in its armed forces, following the unprecedented dismissal of Defence Minister Mykhailo Fedorov and Commander-in-Chief Oleksandr Syrskii within a week. Syrskii was dismissed on 21 July 2026 (30 Tir 1405). Russia meanwhile claimed to be advancing in the Sumy, Kharkiv and Donetsk regions.

The focus of concern is Kostiantynivka in Donetsk, the southernmost of four "fortress cities" Russia pledged to capture by the end of the year. The Institute for the Study of War, a Washington-based think tank, estimated three weeks ago that Russian forces had a presence in just 37 percent of the city, mostly as "infiltrations" rather than firm control; its most recent assessment suggests that infiltration has spread to most of the city. Shortly before his dismissal, Syrskii had painted a more optimistic picture, putting the number of Russian infiltrators in the city at an estimated 145 and their losses at about 25 a day.

Russia's overall rate of advance has nonetheless slowed. The same institute estimated Russian forces were capturing 16.6 square kilometres a day in the first half of 2025, falling to about 1 square kilometre a day in June this year, while in July it assessed Russia was losing territory at 1.6 square kilometres a day. Robert Brovdi, commander of Ukraine's Unmanned Systems Forces, said the number of Russian personnel involved in offensive operations along the front rose 12 percent this month against June and 18 percent against May, with Russian casualties up by similar proportions. Volodymyr Zelenskyy said he had received intelligence that Russia is preparing an "expanded mobilisation" to offset losses of 225,000 this year against recruitment of 221,000. Al Jazeera said it could not independently verify the Russian claims, which have in the past been inflated or premature.