The recent statements by eight retired military generals against an impending invasion or conflict with Iran has revived interest in the subject of free speech in the military. On that point, there is an excellent book worth reading a few chapters from, namely "How The Government Breaks The Law," by Jethro K. Lieberman (Stein and Day, New York, 1973). The book itself is a lively post-mortem of the myriad ways the federal and state governments routinely and systemmatically break the law. But the most relevant chapters here are on the military and free speech issue.
The chapter on military dissidents (p. 93 ff) of course highlights dissent in the Vietnam Era, focusing on how the Navy mis-handled an effort by junior officers called the Concerned Officers Movement (COM) to peacefully protest the official policies concerning "Indo-China." The basic thrust is that the officers planned to meet privately in officer's private residences, on their own time, (cont'd)
to discuss policy, and then carry the fruits of their debates into open forums, such as letters to the editor, speaking at rallies, marches, etc., emphasizing their desire to at all times be responsible voices of dissent on issues of national policy. The Navy cited Article 1247, claiming that active duty officers are prohibited from influencing regulations, etc.
But the chapter goes on to note that elsewhere the Navy violates that very regulation, in part by allowing active duty officers to serve as Assist. Secretaries of Defense, a civilian policy post, without demanding that these officers surrender or resign their commissions. This is one of many contradictions pointed out in the chapter, and all that needs to be done here is call attention to the material again, so that others can refresh their memories and review laws currently on the books, on the very good chance that this material will become even more relevant shortly.
As an aside, the book also points out (p.123 ff) some prison abuses in the US that somewhat resemble Abu Ghraib, which were exercised on US prisoners. The key point the author makes is that those selected as prison guards are generally ill-educated, ill-trained, ill-managed, and that this is done deliberately. Space is too short to recap his argument--all we can do here is leave a trail marker, so that those inclined to follow-up will find a trail that will yield them some benefit.
As a final note, I will just note one of his major summary points: that the entire governmental system can descend into chaos by a number of paths as their institutions begin to fail. See if any or all of these resonate with you: lawlessness, inability to adjust, mistakes, corruption, political pressure, stupidity, lack of professionalism, lack of resources, crisis, and absurdity of the laws.