When you are in England again, speaking English, and feeling like starting a fight, use of the noun "collaborator" = "cooperator", or the verb "collaborate" will not be even remotely effective.
Here, on this forum, English is spoken, and English meanings are meant. It is the case that meanings of words can change with time and it may be the case for historical reasons that the noun "collaborator" has taken on a meaning in Dutch that the verb "collaborate" has not, but you know that (a) I am an English speaker, and I explained to you in detail the actual meaning of the word as written, (b) several other English speakers have confirmed the same thing, (c) the context, yet you still are insisting some insult that was never meant. Readers will have assessed already that you operate in a mode that decides on the conclusion first, finds whatever word/data/fact can be twisted to justify the desired conclusion and then refuses to back down in the face of decisive evidence to the contrary. This reader assessment will not bode well for their belief on your 'factual' or 'data' backed statements on other matters.
Jeroen wrote:http://www.mijnwoordenboek.nl/vertalen.php
collaborator(the ~) als in `traitor to one's country`:
landverrader (de ~ (m))
collaborator(the ~) als in `quisling`:
landverrader (de ~ (m))
collaborator(the ~) als in `collaborator`:
collaborateur (de ~ (m)), landverrader (de ~ (m))
When you are in Holland again, use the word a few times addressing Dutch people and see what happens.