NATO warned Russia on Tuesday that it would use "all necessary military and non-military tools" to defend itself as it condemned Moscow for violating Estonian airspace in a "pattern of increasingly irresponsible behaviour." The warning came after Estonia said on Friday that three Russian MiG-31 fighter jets violated its airspace for 12 minutes before NATO Italian fighter jets escorted them out. The week before, some 20 Russian drones entered Polish airspace, prompting NATO jets to shoot some of them down and the alliance to beef up the defense of Europe's eastern flank.