Yes, english is one of the main languages in aviation... which allows a lot of not-so-good individuals from Australia, Canada, US, UK, to start a pilot career with a definite advantage, thus concealing much of their other weaknesses with their "command of english".
And some of those nations (Ireland, Australia, NZ) enjoy being called "great aviation nations" (because they do supply a big percentage of the pilot workforces of many companies in the world ) ... when they don"t build any aircraft, choppers, fighters, rockets or satellites.
And in the opposite France, Italy, Russia, Israel, even Romania or Switzerland, build a lot of aerospace hardware, feature many Technical Universities and Research Establishments, but their pilots have to work a little bit harder by learning another language (and for some countries, like Belgium, Switzerland, South Africa that will make a total of three)
Now would you consider all those pure-english-speaking pilots, from the previously mentioned countries, having to perform their duties in another language (german, or italian) should it be required by law ? they usually elude the question by saying that its not the situation, and therefore is not to be considered.
We all know that the answer is a big NO, simply because they COULD NOT.
Should it be required by an hypothetical change of the international situation, then maybe a different and more educated branch of their population would have to come forward to fill the cockpits.
And thanks again for ChristiaanJ, for saying that french isn't a technical language... probably the most stupid assertion of all those pages. He will be forgotten anyway - being obviously deprieved of any academic background, I can understand he missed a lot of it, and has no idea of what has been written or achieved in so many fields.
He also displayed in his post the now usual trick, when missing in technical knowledge, to call "possible legal reasons" for help...