The US nuke designs are very weak when compared to the French. The French containment buildings are incredibly strong concrete and steel domes, built on top of huge shock absorbers.
Penny wise, pound foolish...
If the export requires an export license, then you can be sure that: a) The NSA will modify it before it gets to the user or b) It is so bad that the NSA can't be bothered to modify it.
Firewalls are mostly a Windows thing. You don't really need one on a Linux desktop.
You don't even need one on a server either. A server just needs a single rate limiting rule.
That is why Ubuntu ships with no firewall rules.
With your bare hands?!?