Mobile phone footage from the July 31 drone attack showed a plume of white smoke rising near the fulfillment center run by Ozon, Russia’s second-largest online retailer. Somewhere beyond the warehouse, a drone struck the ground with a dull explosion. Since July 18, Ukrainian drones have hit more than a dozen sites across Russia’s network of online retail hubs, killing at least nine warehouse workers and wounding scores more. That warehouse survived unscathed and operations resumed hours later, but the disruptions to business operations caused by the drones are still costly. The immediate costs for Ozon and its larger competitor, Wildberries, which together handle about three-quarters of Russia’s online retail, are easy to see: shuttered warehouses, suspended operations, delayed deliveries and damaged inventory.