Does case carry into an appositive?

Question

I'll ask this question in English, because I'm not sure I could articulate it well enough in German. So this question too is about my essay. The relevant part of the original sentence was

«...die Verantwortung der Verwaltung des Landes lag bei den Alliierten, die Vereinigten Staaten von Amerika, die Sowjetunion...»

I put the countries countries in the nominative, because I thought the dative would only affect "die Alliierten", and when I listed the countries, it was just giving more information. So if I said

«Wir begegneten den Smiths»

and I wanted to list the people in the family's names would I use the dative

dem Peter, der Maria, und dem Max

(I know that it's awkward to use definite pronouns like that but I couldn't come up with any better example)

Answer 1

Appositions indeed agree in case with the phrase that they refer to. Thus, it should be:

bei den Alliierten, den Vereinigten Staaten, der Sowjetunion, …

This is very similar (up to one comma) to a list where den Vereinigten Staaten is the second item, unrelated to den Alliierten. To avoid misunderstandings, you would often introduce the apposition with also, das heißt (d. h.) or similar.

In complex constructions, writers tend to lose track and sometimes produce ungrammatical sentences. For this reason, texts “in the wild” (such as in newspaper articles) may not always follow the rule stated above. Additionally, there are people who consider von + dative to agree with genitive:

der Geschäftspartner von X, seines Vaters, …