Funny. You are joking, right? Whew. I thought so. Besides the superior security model,a linux system is the most flexible platform for building any enterprise class application. While I do love the rock solid platform that we are using (AIX) I lobby for a linux platform regularly.
And Linux with SeLinux enabled should be very well suited for military applications.
Of course I'm just a former NASA engineer with a CISSP cert - so what do I know??? :)