When nations invent weapons do they patent them?

Question

When nations invent weapons do they patent them?

Answer 1

I think a patent is a matter of public record, so anybody anywhere could look it up, so if you wanted a weapon to be secret you would not do that.  Businesses do that, too--the Coke formula is not patented because they don't want it to become a matter of public record, they just keep it secret.

Answer 2

Nations don't always invent weapons - the private sector invents weapons.  Generally, a company like Lockheed Martin or another company produces a weapon for competitive reasons and markets it at arms conferences or armament conferences to military purchasers.  If a nation invents a weapon, it's nationalized as a form of control.  As for patents if a nation invents a weapon, a secret patent is filed protected under national security laws because obviously, a rouge or enemy nation state would want to know by industrial espionage means, what the invention is.

Industrial espionage is alive today, and there have been reports recently of Chinese involvement in spying on American assets.  It will never end.