The Ukrainian air force claimed it has shot down 10 Russian warplanes in 10 days: nine of the Russian air force’s best Sukhoi Su-34 and Sukhoi Su-35 fighter-bombers and also a rare Beriev A-50 radar plane. -snip- The Ukrainian defense ministry announced this month’s ninth and tenth shoot-downs—both involving Su-34s—on Tuesday. “Oops, we did it again!” the ministry quipped. “And now it's 10 destroyed Russian planes in 10 days!” How the Ukrainians are shooting down so many jets is unclear. It’s possible the Ukrainian air force has assigned some of its American-made Patriot missile launchers to mobile air-defense groups that...