Despite continued interest overseas, the COVID-19 pandemic is placing pressure on the foreign military sale program for Lockheed Martin's F-16 Block 70/72 variant -- slowing down negotiations with new customers and work at the new production line in South Carolina, according to multiple sources who spoke with Inside Defense . As just one example of international demand, the Bulgarian government, which last year signed a contract to buy eight new F-16s, is considering purchasing even more jets and has sent...