As you probably know already, Belgium's a bilingual country. The majority speaks Dutch, a large minority French, but historically the French-speaking were dominant.
Anyway, as a result, most Dutch-speaking learned French as a second language, while most French-speakers learned English as a second language. As a result, national meetings tend to be in French - after all, everyone speaks that, right? Of course, being forced to hold meetings etc in a foreign/second language is not conductive to being very convincing or well-spoken... As the Dutch-speaking gained power or however you want to say it, there's been a bit of a reversal - but since the French speaking, in general, don't speak a word of Dutch, we now often have meetings where either everyone will speak their own language, or everyone is obligated to switch language every other sentence, or where we're all forced o speak English, everyone's second or third language. I've seen all of those used in practice, and none of them is good.