15 years? They were under ocupation for most of that time.
It didn't matter, though. They fired rockets on israeli civilians when israel was in Lebanon... AND they fired (and still fire) rockets at israeli civlians in the five years since israel left Lebanon. If anything, their sense of victory increased the number of rockets fired into israel after israel left Lebanon.
Anyway, whatever makes you think Hizbullah cares about Lebanon being "occupied" in the first place, Geni? They enthusiastically support Syria taking over the place, setting up a puppet government; they resist violently any attempt to form a democratic government which will not be a Syrain puppet, or which--heaven forbid--actually demand something from them.
Call me cynical, but if you fire rockets at jews both before AND after israeli left Lebanon, and, on the other hand, openly welcome one of the most opressive thugocracies in the world, Syria, to occupy your country, it's not "the occupation" that's making your lob rockets at israel--it's a desire to destroy israel.
Not that that's too hard to guess: just listen to what Nasrallah, or Hizbullah TV, or their papers, or the children they educated in their "civlian" classrooms, says to you about what Hizbullah's goal is. They, in their own words and actions, repeatedly, consistently, and continously say their goal is to destroy israel and that they will do anything they can to do that.
What more proof do you want, exactly, that that is their real goal?
You're like a defense lawyer whose client just stood up and court and shouted, "Yes! I killed the bastard! That's what I lived for! I'd do it again!", and he mumbles
"But, your honor, you have to remember the late victim had occupied my client's home five years ago, and..."