Ukraine is claiming to have achieved a rare feat in warfare: the shooting down of sophisticated Russian hypersonic Kinzhal missiles. The Russian air force fired six Kh-47M2 Kinzhals at targets in Kyiv, Ukraine's capital, early Tuesday, a weapon it has used sparingly since the early months of its invasion of its neighbour in February 2022. Ukraine has not said if the U.S.-supplied Patriot missiles were used to thwart some or all of the attempted strikes, but it happened 10 days after the military said it brought down another Kinzhal, over Kyiv, using a Patriot missile defence system. The Pentagon also...