The F-5E was developed in the early 1970s as a light tactical fighter. It is an upgraded version of the earlier F-5A. Combat roles of the F-5E include both air-to-air and unguided ground attack. In the United States, it has excelled as an aggressor. Given its mission flexibility, ease of operation, and low cost, the F-5E continues to serve air forces including Iran, Switzerland, and others.