In a development unreported by news media, the State Department’s lead Benghazi investigator, Thomas Pickering, apparently leaked important classified information at a House hearing last week on the Sept. 11, 2012, Benghazi attack. Pickering revealed there is evidence that an Egyptian organization was behind the attack on the U.S. mission that killed U.S. ambassador Christopher Stevens and three other Americans. He further refused to deny there was a plan to kidnap Stevens. Pickering was the author of the State Department’s 39-page Accountability Review Board report, or ARB, which largely absolved then-Secretary of State Hillary Clinton and other top State officials...