I don’t think most Germans would get that pun, at least not fast enough. So “polite chuckle (at recognising the structure of a joke*)” seems right. No, it doesn’t work in German. I shudder to think what the German dub (which is notorious for fucking up anything involving clever language) may have done with this.

Disregarding the language barrier, WWI is kind of overshadowed in public discourse by that other war so it’s not like we have strong enough feelings about it to be upset about a mildly amusing joke.

* no our lack of humour does not impair our ability to recognise that a joke has occurred fuck off ;P