The Ukrainian air force’s Dolgintsevo air base is one of the most vulnerable bases in Ukraine. Situated near Kryvyi Rih just 45 miles from the front line in southern Ukraine, the base is within range of Russia’s best Lancet drones. Since the extended-range version of the Lancet—the so-called “Product 53”—debuted in August, the drones have attacked Dolgintsevo every few weeks, aiming for any warplanes parked in the open at the base’s tarmacs. In nine months, Lancets have struck at least four jets at Dolgintsevo: two Mikoyan MiG-29s and two Sukhoi Su-25s. The first two strikes, last fall, took the Ukrainian...