Almost all our doctrine is "Approved for Public Release, Distribution Unlimited."
And how, pray tell, does US military doctrine enter into any kind of serious conversation?
Broad discussions about doctrine and force structure are unclassified, in fact it would be hard to have them in a classified environment. People would notice that the Marines have coughed up all their tanks and reclassified or transferred to the Army all their tankers.
Almost all our doctrine is "Approved for Public Release, Distribution Unlimited."
Actual campaign, operational, and contingency plans are mostly classified at various levels from "UNCLASSIFIED//FOR OFFICIAL USE ONLY" through compartmented TOP SECRET plans.