Oogle is correct. The JAA system is designed to keep out those who did a licence somewhere else, and if you do want to fly there, then they will extract a large sum of cash from you, to pass exams you have already sat else where...sort of like a penalty really.
If they were really worried about others standards, they would let you sit a "Bridging" exam, or even let you sit the exams without doing an "approved" ground school course. If I know the theory, why won't you let me sit the exams??? "Ahhh, but without the ground school we don't know if you are at our standard" ...Well if I pass your exams, then I guess I must be...
I thought the "I" in ICAO stood for international?