Sometimes I think Cyteen and all the related books set in the Alliance-Union Universe are about the Cold War. Then I remember Regensis. *sigh* Cyteen is set in a universe where there are two interstellar empires, both approximately alike in dignity, bitterly opposed to one another. Some planets have one kind of government and economic structure, and others have a different one, with mutual hatred and contempt. (And spies and merchants and space stations with uncertain loyalties.) Each central government builds up its military in case of invasion, but even without war it's impossible to ignore the other empire...you have to defend against spies, you have to win hockey games or go to the moon or whatever to prove you're better than the other empire. It was published in 1988, and likely written earlier.

Regenesis is a sequel written 20 years later, but the plot picks up the same month. (Possibly even the next day.) None of them notice that they are suddenly living in a world with a SINGLE superpower. All the planets are suddenly working together in a Coalition of Everybody But Terrorists. It's not like they never read the newspapers! These are people close to the corridors