Between 1953 and 1954, he commanded the Planning Department of the
General Staff. Between 1954 and 1955, he headed IDF chief of staff
Moshe Dayan's office, where he was present at weekly meetings with Dayan, then-Defense Minister
David Ben-Gurion, and then-director general of the ministry
Shimon Peres. In April 1973, Egyptian spy
Ashraf Marwan warned the Mossad that Egypt and Syria would attack Israel in May. Zeira did not believe his warning, and he also doubted Arab military capabilities, stating: "A logical analysis of the situation will show that the Egyptians would make a mistake if they went to war". When no attack occurred, Zeira suspected that Marwan was a
double agent attempting to sabotage Israel. A day after a secret meeting by King
Hussein of Jordan to the Mossad guesthouse north of
Tel Aviv on September 25, 1973, in which he warned of an imminent war, defense minister Dayan held a meeting with Zeira and his deputy,
Aryeh Shalev, where they dismissed his warning as too vague. After Egypt conducted a large military drill on the
Suez Canal on October 1, he dismissed the threat of war as "very low". On October 6, Egypt and Syria began a coordinated attack on Israel in the first stage of the Yom Kippur War, catching Israel off guard and leading to heavy losses. Zeira did not activate these means despite requests from his own staff and Elazar because he was convinced that Egypt would not attack Israel, and believed that activating the means would risk exposing them. Zeira called the findings baseless, and wrote in his autobiography that "thus the entire blame was placed on those in uniform, and the political leadership came out clean". He argued that the Mossad was responsible for Israel's shortcomings by listening to Marwan, who he claimed was a "double agent" who misguided Israel. The commission did not directly call for Zeira's dismissal, but he left Israel to study at
Stanford University and resigned from the IDF anyway, at the age of 47. == Later life ==