Really? Is that what this is about, "everything"? That's a pretty broad statement.
We're talking about documents that reflect confidential discussions between American foreign service officers, their subordinates and superiors as well as their conversations with their foreign colleagues to include leaders of foreign countries.
You can't see ANY possible reason why these conversations should stay out of the public domain?
There are materials that have to be classified but it should be directly related to our nation security.
National security covers many things. Need I spell out everything so you could understand.
If the conversations are “professional” in that they hold the other nations and leaders in proper respect then why should they be classified?
Granted things which talk of exact/non-hypothetical weapons and defenses do have some justification for being classified... but I think it would ALSO so us well to remember that Tom Clancy’s Hunt for Red October got him pulled in front of Congress [I believe] and questioned for the breaches of security regarding classified capabilities of submarines (which he reconstructed from non-classified sources if I remember).