> I think a better case could be made for the Klingons being racist caricatures, since in TOS their look was intentionally based on Asiatic and Mongol people in order to make them seem more frightening and villainous.

In my head-canon TOS Klingons are Russia and Romulans are China.

Reasons for this;

- Star Trek 6 (The whole thing is an allegory for the end of the cold war, right down to Praxis being a stand-in for Chernobyl)

- That fight scene in 'The Trouble with Tribbles' that strikes me as 'feels like a rehashed tale about a barfight between Allied and Soviet soldiers in pre-split post WW2 Germany'

- Romulans being more 'secluded' and more about political and legal intrigue than violence (If we consider Klingon direct violence a stand-in for USSR/Russian 'maybe put in house arrest before we assasinate' vs China's 'throw the rigid legal book at them')