The IAI Lavi (Hebrew: לביא, "Young Lion") was a single-engined fourth-generation multirole jet fighter developed in Israel, by Israel Aircraft Industries (IAI), during the 1980s. The decision to develop the Lavi was controversial, both with the Israeli public, due to the enormous associated costs, and particularly with the U.S. government due to competition with American jets on the export market. By 1984 Israel, with a population of 4 million, had the world's highest military expenditure as a proportion of GDP, at 24%, a rate of spending considered unsustainable. These issues contributed to the ultimate cancellation of the aircraft, by the Israeli government, during the flight-test phase of development in August 1987. The Lavi performed successfully in flight-tests, with its flight handling described as "excellent" by test pilots. The Lavi was planned to be the mainstay of the Israeli Air Force, and considerable export sales for the aircraft had been forecast. The uniqueness of its design was in the combination of a small, aerodynamic, highly maneuverable plane, with sophisticated, software-rich systems, low armed drag, and the ability to carry a large payload at high speed and over long distances. As of 2012, two of the prototypes have been preserved, and have been placed on public display. The Israeli cabinet's late-stage cancellation of the program, by a 12–11 vote, continued to arouse controversy and bitterness in Israel for decades, with Moshe Arens stating in 2013 that if the project had not been cancelled the IAF "would be operating the world's most advanced fighter, upgraded over the years to incorporate operational experience and newer technology." Development Origins Conceptually, the Lavi had its origins in the idea espoused by IAF commander and Minister of Defence Ezer Weizman that Israel's combat aircraft should fall into 'two-tiers' – a small number of high performance aircraft and a larger bulk with less sophistication and complexity. In the mid-1970s, the plane that was to become the Lavi was meant to be a multirole fighter-bomber to replace aging IAF aircraft such as the Douglas A-4 Skyhawk and IAI Kfir; however continuous revisions of the proposed aircraft led to the incorporation of more advanced technologies and ideas to produce an ambitious aircraft in the class of the American General Dynamics F-16. The IAF was estimated to have a requirement for 300 aircraft, 60 of which were expected to be combat-capable two-seat trainers. In February 1980, a milestone towards the development