In the late 1960s the Israeli Military Air Force was comprised primarily of the French built Dassault Mirage III fighter jet However the Israeli General Staff felt they needed to make some changes to the basic specifications of this aircraft The Mirage III proved very effective in the airsuperiority role but the Israeli military determined they needed more of a groundattack aircraft Some of the sophisticated all weather fighting systems could be removed to make room for increased fuel capacity for longer ground attack missions It would also help in reducing maintenance costs This revised aircraft would be known as the Mirage M 5J & 50 Mirage 5 Js were paid for by Israel But then in the summer of 1967 the Six Day War everything changed With the start of the Six Day War the French government imposed an arms embargo on Dassault & the aircraft could not be delivered The Israeli Military felt that the Arab countries could gain the upper hand if something was not done & done quickly The Mossad stepped in who launched a covert action & acquired the blueprints to the Mirage III all 250 000 pages of them It has gone down in history as one of the biggest espionages cases ever exposed The actual first version built off of these plans was called the Nesher Eagle & built totally in Israel The biggest difference in the design was the modification to accommodate the General Electric J79 turbojet the same engine used in the F4 Phantom This more advanced power plant gave the aircraft far better performance than the older Mirage III After numerous revisions & improvements the Kfir which translates Lion Cub in Hebrew finally entered service in 1975 Its role as the primary air superiority aircraft of the Israeli Air Force was very short however In 1976 Israel started to take delivery of F15 Eagles from the United States They were used more for ground attack missions throughout their service life until 1990s when they were withdrawn from active duty