On a practical basis, get real. Passing nuclear secrets is attempted murder and an act of war.
Of course it is, which is why most countries have limits on free speech such as no giving out secrets to do with national security. Only America has no limits written into their constitution and then has unwritten limits which just encourages the fucking politicians to ignore their constitution. Once they're used to ignoring the highest law in the land it comes easy to ignore the other laws. And the American people just go along with it and keep voting the same arseholes in over and over.
Free speech is really important and should have the minimum limits possible but it turns out there are necessary limits like the old "loose lips sink ships"