A language is a tool, not a nationality or a border.

Your average educated European speaks at least three, one of which is English because it is a good language to have because it is the language of international commerce. This has been the case since many decades and has nothing to do with using the language internally.

But: many people do use it internally. French tourists abroad are more likely to use English than French. European colleagues usually standardize on English, both for their communications as well as for their documentation needs.

Scientific literature is predominantly in English (at least, for now).

So there are many reasons to use English which have nothing to do with allegiance or dependence.