Joan my command of history is not the greatest but since so many wars have been fought with mercenaries from other countries and sent to even different countries like our Revolutionary War speaking English or the language of the country is not needed as long as those in charge can get their orders understood. Believe me talk to any WW1 veteran and learn that their not knowing or understanding French did not keep them from fighting in that war but it did get a lot killed because of not understanding key words. Of course there are no veterans left anymore from that war. In battle you are not always under the command of your own forces.