Coz' the same aswer applies to your point. "Saarland was never claimed as a french territory.Alsace/Lorraine was and has been in fact annexed by France" - unconditional surrender After a war you can not just take land off the defeated. You need to get that defeated party to sign a surrender document that says so, or get them to sign a treaty that ceded the land. A signed "unconditional surrender" document is just that - the defeated party has signed a surrender that allows the victors to do what they want and take what they please. France decided to take Alsace/Lorraine, and it was within its rights to do so. Israel has no such signed document with Syria, and so it has no sovereignty over the Golan. Therefore they don't "own" it, they "occupy" it.
from the article: Syria diplomat: No preconditions to negotiations with Israel