knack for shooting down planes in mind

Another consideration is that these assets could be needed in a larger potential war with NATO. Russia has kept much of its airpower and some of its most advanced aircraft out of the war in Ukraine. Defense experts say doing so signals Russian worries about Ukraine's air-defense game but also considerations beyond this fight to one with NATO. John Baum, an airpower expert at the Mitchell Institute who's a retired US Air Force lieutenant colonel, told Business Insider that the Russians "could bring more-advanced aircraft into the fight" but that "they simply haven't done that yet." Some Kremlin claims aside, there's no evidence Russia has used its Su-57s over Ukraine itself, despite the aircraft, at least on paper, being Russia's most advanced plane and supposedly built for a war in which the airspace is heavily contested.