Prior to 2000, Israel was in Lebanon and had good relations with the Lebanese Christians. Christian Arabs were allowed to travel back and forth between Israel and Lebanon. When Israel left, some of them had to become refugees in Israel. Lebanon is not in control of its own country. Hizbullah rules the South and Iran and Syria run the show.
The Lebanese welcomed Israel after liberating their country form PLO occupation. There was going to be a peace agreement with Lebanon but then the leader was assassinated. Israel let the PLO into Israel in the end so anything achieved in Lebanon was in vain in the end, especially after Israel was there for 18 years with many Jews dying.
The Lebanese Parliament has to have a certain number of Muslims and a certain number of Christians in Parliament. The President has to be Christian and the Prime Minister has to be Muslim. It seems like Lebanon's government is just a puppet government. Beirut was the Paris of the Middle East. Now Paris is becoming the Beirut of Europe.
If Israel offers aid, it should be for civilians. Israel should not address Hizbullah. The President is a different story. He's not even Muslim.
Southern Lebanon is definitely part of the Land of Israel with the same status as the Galilee. All of Lebanon is certainly part of the Greater Land of Israel.