> France doesn't "protect" Champagne
Oh, but they do. This goes a lot beyond simple geographical "truth in advertising", and is indeed a lot more similar to a trademark. As you mention, it's not enough for a wine to be produced in the region of Champagne to be allowed to be called Champagne, it has to be produced within very narrow parameters. Jamon Iberico is indeed protected, and again, there's quite a bit more going into this than ham produced on the Iberian peninsula. It's more pronounced with feta cheese, which does not have a geography in the name, yet have to be made in particular areas of Greece.
This is not to say this is bad, trademarks are generally a good thing, but let's not pretend there aren't strong protection-motives at play.
(As an aside, the process also sometimes backfires and inhibits innovation as in the case of "super-Tuscans", some fantastic wines produced in Tuscany, but not qualifying under the Chianti protection, and instead was released as table wine, ie. the lowest classification, while Chianti had languished as a profoundly mediocre product.)