NATO and the EU on Wednesday sought ways to boost anti-drone defenses, as Europe scrambles to counter the threat from Russia after a series of air incursions. High-profile incidents in Poland and Estonia have set off a flurry of activity from European officials to plug gaps in the continent's defenses. NATO has launched a new mission and beefed up forces on its eastern border, but it is playing catch-up as it tries to tap Ukraine's experience and get to grips with the drone threat from Moscow.