Eh, maybe. 20 years would put you in the late 60s&#x2F; early 70s for thermonuclear bombs, I think. I could see it staying classified for a while past that. And, if releasing the information will put someone&#x27;s life in danger, sure. But I suspect situations like this account for a fraction of a percent of stuff that stays classified for decades.<p>If the reason the government keeps something classified is to protect a person&#x27;s career, or (as I assume is usually the case) just because they <i>can</i> so why go to the trouble of declassifying it, that is not a good enough reason. The default state of information held by the government is that it should be public domain, and anything classified ought to be scrutinized heavily - and <i>regularly</i> - to confirm it should be so and should remain so.