Since the beginning of Russia's full-scale invasion, the city of Kostiantynivka in Donetsk Oblast has been a pillar of Ukraine's defense of the Donbas region. Now, amid Moscow's summer offensive campaign, Russian forces are closing in on the city from three sides. Increasingly, the fighting here is defined by a gray zone that constantly gets deeper and more deadly, as both sides adapt their tactics to the drone-infested battlefield. The Kyiv Independent's Francis Farrell and Olena Zashko spent