Al Qaeda leader Ayman al-Zawahiri was killed Monday by America’s secretive and gruesome R9X Hellfire missile — which is also known as the “flying Ginsu.” The strangest variant in the Hellfire family of missiles — built as a precision weapon of targeted assassination — the R9X’s most distinguishing characteristic is that it doesn’t explode and simply uses its weight, momentum and blade-like appendages to kill. First revealed by the Wall Street Journal in 2019, the modified R9X trades the standard Hellfire’s explosive warhead for a halo of six metal fins that look like swords and are sharp enough to slice...