IN A SLEEK business tower in Kyiv, a group of engineers huddle around a new, carbon black attack drone called Batyar, the “rogue”. It looks a near analogue of the Iranian-Russian Shahed drones that have been terrorising Ukrainian cities for the past few months. With a range of up to 1,500km, a cost of just $25,000, and an optical terrain-recognition system that renders it resistant to most electronic jamming, the model is likely to offer its Russian rival stiff competition. It is the joint effort of Ukrainian and American firms, one of many collaborations where technology is shared and refined in combat. “Big American corporations are frightened,” says the Ukrainian officer co-ordinating the project. “They know that they can’t compete.”