It was just after midnight on March 21, 1980, when a Navy destroyer navigated by Stephen Bannon, a junior officer, met with the supercarrier USS Nimitz in the Gulf of Oman. The convoy headed near the Iranian coast, where a secret mission would be launched a month later to rescue 52 U.S. Embassy hostages held in Tehran. Bannon's ship, the USS Paul F. Foster, trailed the Nimitz, which carried helicopters that would try to retrieve the hostages. But before the mission launched, Bannon's ship was ordered to sail to Pearl Harbor, and he learned while at sea the rescue had...