I don't know those software or how widely utilized they are in the US and specifically in US national security critical systems.

The US in a unique position, though. Windows and OSX are operating systems; they have complete control of everything else running in the systems they run on. Google has view of the world's web navigation, email authentication, as well as complete control over a grand portion of the world's phones (most of the other portion is controlled by Apple, also a US company), including knowledge of phone calls made between people, and their location at all times. Facebook also has great knowledge of how all people are interrelated.

There's probably lots I'm missing, but the point is that most of the world's cyberspace (a useful word apparently) is controlled by the US. If we translate that to cyberwarfare, that means that the US practically has ALL the guns. A couple guns from other nations are not going to make a difference in this space.

At least Kaspersky was well deployed within DHS and DoD: a ban was set to prevent new deployments: http://www.executivegov.com/2018/06/dod-nasa-gsa-issue-inter...

The problem is not the OS, the problem are the now the backdoors in the CPU's. In all of them. With them you get even into a foreign OS, like L3 or OpenBSD.