Bring back ArpaNet!
Or whatever the military's precursor to the internet was.
A private WAN for the military seems like the right idea, but I don't like it for a couple reasons. First of all, it's expensive. I don't mean just to build, but to maintain as well. We've already got a great infrastructure throughout the country, as well as the world, maintained mostly by private telcos. If the military builds their own WAN, not only do they have to lay a bunch of new lines, but then you have to get people to maintain them. And these are all services that we already have in place. What's the point?
But you're the one that works in telco, so I might be wrong about that. Private corporations are the ones building and maintaining all the networks though, right?
I much prefer the idea of developing custom codecs for video and pictures. That would also be a pain in the ass to maintain though, because they wouldn't leave it alone, now you have to update everybody's computer when there's a change.
Maybe just have a basic firewall solution? Have some servers in the intranet, some servers that are used throughout the nation, and only allow traffic amongst those. It'd function the same as a private intranet (though with the added security risk of being accessible to the world), but would leverage the networking infrastructure we've already got in place.