Similar words, which are not of German origin, such as communist or socialist are not spelled with a capital. Equally Zeitgeist, and Blitzkrieg are also given capitals, but interestingly not kindergarten or bratwurst.

Do you capitalize battles?

Capitalize the names of wars and major battles.

What is the rule for capitalization?

In general, you should capitalize the first word, all nouns, all verbs (even short ones, like is), all adjectives, and all proper nouns. That means you should lowercase articles, conjunctions, and prepositions—however, some style guides say to capitalize conjunctions and prepositions that are longer than five letters.