A new book by veteran Israeli intelligence expert Uri Bar-Joseph tells the story of the Angel, Marwan’s code name, in detail. This is a tale of espionage at the highest level. The Angel provided Israel with Egypt’s entire order of battle for its armed forces and Egypt’s war plans for attacking Israel across the Suez Canal. He provided details of Sadat’s meetings with the Soviet leaders and up-to-the-minute reports on Soviet arms deliveries to Cairo.So despite clear warnings from their top agent the Israelis were surprised by Egypt's 1973 attack across the Suez Canal, and it took them hard fighting and good luck to avoid losing a whole infantry division to Egypt's pincer attack.
But the Israeli military intelligence experts in the Directorate of Military Intelligence, which was solely responsible for producing the national intelligence estimates on whether Egypt would go to war, were convinced Sadat would not take the risk. The DMI had a concept of war planning. In the concept, Egypt could not beat Israel because of Israel’s overwhelming air superiority, which Egypt’s leaders knew made war suicidal. Thus Sadat wouldn’t attack.
The story doesn't get any better after the war. Eli Zeira, the chief of Israel's Directorate of Military Intelligence, faced hard questioning about why he had not taken Marwan's warning seriously. He responded by launching a covert campaign to smear Marwan as an untrustworthy double agent, eventually leaking so many details about his spy that Marwan's identity was exposed by the press, leading to his murder in London in 2007. Now that's a great way to encourage future agents to risk their lives for you.