Re: Protectionism vs. security
An "N.I.H." posture with respect to national defense should be considered 'prudent'.
And open source stuff could simply be 'hardened'. BSD comes to mind, in that regard. Linux too, if the GPL is simply ignored for national security reasons. But if it's kept a secret, nobody would know [or disclose it] so there ya go.
As for anti-virus and security tools, if it's closed source and NOT a U.S. based company, and/or phones home with any data, it's by definition 'insecure' and shouldn't be in use by the military or any government agency that deals with classified information.