Last year I arrived early for a lunch address by Gen. Michael Hayden, who ran the National Security Agency and later the Central Intelligence Agency in the George W. Bush administration. Hayden was already there, and glad to chat. The conversation turned to Egypt, and I asked Hayden why the Republican mainstream had embraced the Muslim Brotherhood rather than the military government of President al-Sisi, an American-trained soldier who espoused a reformed Islam that would repudiate terrorism. “We were sorry that [Muslim Brotherhood leader Mohamed] Morsi was overthrown” in July 2013, Hayden explained. “We wanted to see what would happen...