He studied at the Hebrew Reali School, and began his national service in the Israel Defense Forces in 1963, joining the Israeli Air Force as a fighter pilot. In 1967, he fought in the Six-Day War with 109 Squadron. He was one of the first Israeli pilots to fly F-4 Phantom jets, and was also one of the founders of 69 Squadron. He fought in the War of Attrition of 1967-1970, participating in Operation Priha and Operation Rimon 20. The outbreak of the Yom Kippur War in 1973 found Sella in the United States studying at a professional course; he returned to Israel and fought in the war as deputy commander of 69 Squadron. In total, he shot down five enemy aircraft during his service. Between 1976 and 1979 he commanded 201 Squadron, and between 1980 and 1983, he served as the Air Force's Director of Operations. He commanded Operation Opera, the air strike against the Iraqi Osiraknuclear reactor in 1981, and was a commanding officer in Operation Mole Cricket 19 during the 1982 Lebanon War. Sella participated in the 1982 Lebanon War and took part in Operation Mole Cricket 19. Afterwards, he took a sabbatical to the United States to study, and earned an MA in computer science at New York University. While pursuing a PhD, Sella recruited Jonathan Pollard to spy for Israel. The US indicted Pollard on espionage charges in 1987. Pollard's Israeli handlers were granted immunity from prosecution in the United States in exchange for cooperation after Pollard's arrest. Sella's role, however, was unknown at the time and the Israelis were not forthcoming about his involvement. For this reason, Sella was not given immunity by the US when his role was uncovered. Israel then refused to extradite Sella for questioning. In March 1987 a Federal grand jury indicted Sella in absentia on three counts of espionage, with a maximum sentence of life imprisonment and a $500,000 fine. After Sella was promoted to Brigadier General and given command of Tel Nof Airbase, the U.S. Congress reacted by threatening to cut aid to Israel. U.S. officials in Israel were instructed to have no contact with Sella or with the airbase so long as he commanded it. Israel refused to relieve him of his duties, creating tensions. Sella then resigned to defuse US-Israel tensions, and was subsequently appointed an instructor at Israel's National Security College. Sella completed his PhD at Tel Aviv University's Faculty of Management and earned a degree in economics from the Hebrew University of Jerusalem. In 1990 he founded "Sibm", an IT company, which acted as a consultant on information systems. In September 2003, he sold his company - which had 40 employees - to Matrix ID Ltd and became director of strategic consulting at Matrix's Security Division. From 2005 to 2006, he served as chairman of the Adam Milo Institute in Jerusalem. He also became a business partner of Alexander Beer, a brewery based in the Emek HeferIndustrial Park.
Personal life
Sella is married to Yehudit, a lawyer, and has three children.