Hezbollah is somewhat of the successor organization of the most militant wings of groups like the PLO and Fatah, so I think it is relevant to speak of Hezbollah as in some sense existing in a nascent form prior to its founding

First, I forgot an 's there - I meant 1970s. Second, unfortunately for Lebanon, Hezbollah wasn't the only terrorist organization growing in it [0]. "The proximate cause of the Israeli invasion was the Coastal Road massacre that took place near Tel Aviv on 11 March 1978"

[0] https://en.wikipedia.org/wiki/1978_South_Lebanon_conflict

Hezbollah was founded in 1982. With benefit of hindsight we can see that while Israel's Lebanon Invasion in 1980s was successful in curbing the PLO who perpetrated the massacre, they created a more formidable adversary in form of Hezbollah.

So maybe Israel invading Lebanon in the late 1970s wasn't the best idea. I guess they should have time-traveled to 2024 and consult with you, but unfortunately that didn't happen. However my point wasn't that the invasion was a great idea, but that the initiator of the conflict between Lebanon (or Hezbollah) with Israel is Hezbollah.