The Russian army is losing at least a battalion’s worth of vehicles and men daily as twin Ukrainian counteroffensives roll back Russian territorial gains in eastern and southern Ukraine. That’s hundreds of casualties and scores of vehicle write-offs every day. These losses catastrophic for Russia. Russian army barely was sustaining a little over 100 under-strength battalions in Ukraine before Kyiv’s forces counterattacked in south on Aug. 30 and in the east eight days later. In under two weeks of brutal fighting, the Ukrainians have destroyed, badly damaged or captured 1,200 Russian tanks, fighting vehicles, trucks, helicopters, warplanes and drones, according...