In 1948 Margo had started a flourishing career as a trial lawyer aided by his record as a war hero. One day, he returned to his chambers from Court and found an urgent telegram from David Ben-Gurion. Ben Gurion asked Margo to come out to Israel to serve as Ben Gurion's chief advisor on the establishment and organization of the Israeli Air Force. Though he had been in combat for years as a pilot in World War II and now had a wife and small child, Margo later wrote in his memoirs that he felt he had to go. The newly declared State of Israel had been attacked by the armies of five Arab countries and its prospects for survival were dim. Ben Gurion, who knew that air power would be critical to Israel's immediate and long range survival, had heard of Margo from his commanders such as Yaakov Dori and Chaim Laskov. Margo's effectiveness as a squadron commander, his expertise in air warfare in both the Desert and Europe during World War II, and his experience of high level command in the Royal Air Force as Operations Staff Officer, Advanced Air HQ, Desert Air Force, made him ideal for the job.