[Tsuwabuki]

Read Honor Harrington, where English is only the language of the Solarian League, the Star Kingdom of Manticore, and Grayson. The Anderman Empire speaks German and Mandarin. The People's (later Restored) Republic of Haven speaks French. There is at least one Japanese speaking star nation. It is also much more like sub warfare, and missile ranges are extreme and done, sometimes, without foes being anywhere near visual range.

As far aliens? There are no aliens, except for some fairly neolithic multi-armed "protectorates" of the Star Kingdom. Humans are pretty much alone in the universe.

Honestly, the answers are simple. Science fiction always takes what we know to be true, but do not want to admit it, and disguises it just enough so that we can deal with it. Science fiction, especially of the kind you mention, is intentionally set up to speak about humanity, and not to attempt to create a well founded, extrapolated picture of xenobiology. If you're looking for some kind of survey course to how life might develop elsewhere than Earth, you would be better served by visiting the closest major public university.


Also, about it being just the US: You're wrong. See Uchuu Senkan Yamato, for Japan. I am sure there are others for other countries.