It's the US who puts sanctions on companies working with foreign military organizations and manufacturers. So, they can't freely buy chips for rockets, for exam

It's the US who puts sanctions on companies working with foreign military organizations and manufacturers. So, they can't freely buy chips for rockets, for example. But their PCs use Intel chips and Microsoft Windows OS. Microsoft opens their source codes to security services of different nations, including Russia and China. There are of course Linux distributions which are supposed to be used by army, but no one really uses them.