A JAR ATPL entitles you to work in any country in Europe. The international language of aviation is English - unless of course you wish to work in Europe, where you are required to speak fluent French, German, Dutch or whatever before you can join their airlines.
Needless to say, they can all join ours. They wouldn't be protecting their own nationals, would they? NAH, that's just me being cynical again, innit?