You can't actually know that, so stop deluding yourself.
Not conclusively, but we can speculate, especially since a number of places have significantly reduced enforcement and a few have legalized. We can also draw a number of parallels with alcohol prohibition.
Apparently it isn't, as seen by the lasts 35 years.
Is it tough politically? Yes. Is it tough to actually write laws better than our current ones? No.
Like other federal agencies, the NSA is compelled by law to try to commercialize its R&D.
The closest thing I'm aware of is Bayh-Dole, which applies to grants from non-federal agencies. Such a policy would seem contrary to our philosophy on copyright regarding federal entities, which prohibits them from obtaining copyright on works created by the US government. I realize that copyright and patents are two different entities, but they have very similar intentions in their constitutional basis.
The key elements in human thinking are not numbers but labels of fuzzy sets. -- L. Zadeh