Designed to be lighter, cheaper, and easier to field than its contemporaries, the F-5 Tiger nevertheless had an arduous road to acceptance in the USAF. It was used operationally in Vietnam and as an "aggressor" training aircraft for multiple units. Overseas, however, it was far better received by countries like Switzerland, Singapore, Taiwan and more. There, its high mission availability and low cost count for far more than some of the dubious advantages of larger, more complicated craft. The RF-5F was a recon version.