> the idea that you can keep a secret that 100,000+ people are in on is just silly

100,000 would be hard, but 10,000 vetted employees threatened with the power of the state for the rest of their lives is definitely done in militaries all over the world.

Look at the never ending revelations about the early Soviet era. Many aspects of the GULAG system are only becoming clear now.

I do not find the argument that governments can't keep secrets convincing at all. Even if the seal isn't airtight there is often such a highly effective ability to muddy the waters the truth becomes impossible to see through the disinformation.