Key Takeaways from the ISW: Russian forces recently made tactical gains in Kostyantynivka – Russia’s assessed main effort for the Spring-Summer 2026 offensive. Russian forces began their campaign for Kostyantynivka in Summer 2025 after completing the seizures of Chasiv Yar and Toretsk – settlements northeast and southeast of Kostyantynivka, respectively. Ukrainian forces conducted a FP-5 Flamingo cruise missile strike overnight on June 9 and 10 against a Russian military plant that produces key components for Shahed drones and missiles. Russian forces will likely make tactical gains in Kostyantynivka in Summer 2026 but are unlikely to make operational gains against the Fortress Belt writ large. Ukrainian forces also continued their long-range strike campaign against Russian oil infrastructure on the night of June 9 to June 10. The Kremlin’s volunteer recruitment campaign continues to show signs of strain under the pressure of high battlefield losses and rising economic costs. The Kremlin continues attempts to nationalize private assets of Russian citizens, likely to support state revenues and the costly war effort in Ukraine. Ukrainian forces recently advanced in the Kostyantynivka-Druzhkivka tactical area and in the western Zaporizhia Oblast. Russian forces recently advanced in the Kostyantynivka-Druzhkivka tactical area. Russian forces launched 207 drones against Ukraine overnight. JOIN US ON TELEGRAMFollow our coverage of the war on the @Kyivpost_official. See the original here.