I can answer about Soviet Union.
Short answer: the authors of Red October are right. In the military, the only permitted way to address a fellow officer was: "Comrad Leutenant", "Comrad Captain", etc. An officer addressing a private could omit comrad, and simply say "privat".
In the military, only close friends, when they were alone could call each other first names.
Long answer.
Addressing as "comrade" (товарищ) was very common. First: it was mandatory for communications of the members of communist party between themselves, and in the military. But also common in other situations, especially in official communication.
Also common and more neutral was "citizen" (гражданин (m), гражданка (f)). These were the only two admissible ways to address a person whose name you do not know. In the cases you know the name, the polite form was "first name, patronim", without adding "comarade" or "citizen", or for a close friend or relative, one could use first name only. More official was "comrade" followed by the last name.
The word "comrade" was grammatically masculine, but had no feminine form, and was used for addressing women as well. The word
"citizen" had two gender forms, as I indicated above.
There were some subtle differences in using "citizen" and "comrade", which are hard to explain. For example, police will address you only as "citizen",
and fellow workers in a meeting only as "comrade" followed by last name. You could address Stalin only as "comrade Stalin". Every Soviet citizen perfectly knew when to use "citizen" and when "comrade", but the general rule is hard to state.
I cannot write an essay describing completely all ways Soviet people addressed each other, it will be too long. In daily life, it depended on who is talking to whom. And it changed during the Soviet history.
If you know the person's name, the standard way was to address him/her by name.
For example, suppose that the person's full name was Piotr Illich Chajkovskii (first, patronim, last. Patronim is the name of the father with the suffix -ich for men and -vna for women). His wife will probably address him as Petia (diminutive of Piotr). A close friend will use either Petia or Piotr. Other people will say
"Piotr Illich". In more official situation,
"comrad Chajkovskii". But a policeman only
"citizen Chajkovskii".
Remark. Russian counterparts for Mr, Ms, Sir, Madam, etc. were abolished after the 1917 revolution, so the ways to address a person that I described were the only possible (polite) ones. (Before 1917, addressing was extremely complicated, because it had to reflect the rank of a person. There were 14 civil ranks, corresponding to military ranks,
and separate ranks for nobility).
After 1917 this created a certain lack of proper way to address an unknown person. For young persons, one could use: "boy", "girl", "young man",
"young lady" (мальчик, девочка, молодой человек, девушка). In the later years of Soviet Union, this was spread by some people to addressing all people who could be addressed as "man" (мужчина),
"woman" (женщина), or even "grandfather", "grandmother" (дед, бабушка). This usage came to the daily language from the criminal jargon, and was considered somewhat rude. Originally (before 1940s) addressing an unknown man as "man" was used only by prostitutes.
After collapse of Soviet union they gradually returned more or less to the (reduced) pre-revolutionary usage
(господин, госпожа) which corresponds to Mr., Ms. In Ukraine, they switched back to Pan/Pani, similar to Polish.
Some people hated "comrad". They could answer
to this: "Wolf of Bryansk is your comrad!"
Брянский волк тебе товарищ! (Bryansk is a region famous for its dense forests).
References. I lived in Soviet Union from 1950s to its end in 1990s, served in the army, worked as a construction worker, and in farms, and as a teacher/researcher; my native language is Russian, and I read a lot of Russian literature and newspapers.
