Hm. This is a normal practice for companies that do mostly ITAR work. See also NASA: https://www.nasa.gov/careers/working-with-nasa https://www.nasa.gov/career

Hm. This is a normal practice for companies that do mostly ITAR work. See also NASA: https://www.nasa.gov/careers/working-with-nasa https://www.nasa.gov/careers/working-with-nasa "Other than extremely rare exceptions, you must be a U.S. citizen in order to work for NASA as a civil service employee." You can google up similar examples at other contractors that mostly do ITAR work. When there are exceptions its mostly in the form of alternative facilities in other countries (which usually require you to be a citizen of those countries).