If these foreign contractors did all the R&D and built all the system's they manage, is it really American IP? Is it because the company is headquartered in the USA? What about Apple and other large American tech companies that keep the majority of their financial and IP holdings in Ireland for tax purposes? Surely Ireland should impose similar restrictions to keep Irish IP at home?
What you're asking for is basically impossible given the state of globalization today. Given how easy it is for tech companies to hire wherever they want, and how easy it is for information to flow over the internet's tubes, I'd suggest moving to a different industry if tech offends your nationalist sensibilities.