They'll need lots of ammo, and very likely lots of help. And they aren't going to get it.
It took a Syrian invasion to end the (Syrian / PLO caused) civil war in the 1970s, and there hasn't been an independent Lebanon since. The US did basically nothing when the terrorists and Moslem militias under Syrian influence destroyed the brokered solution and murdered the president in his palace.
Jumblatt, leader of the Druze, is against Syrian domination, but as long as they leave him some autonomy (prior to his eventual assassination by them or their proxies) he will not lift a finger to fight anyone unless directly attacked.
There is alot of weapons in lebanon, most families tend to have mini arsenals of weapons...After the disbanding of the militias at the end of the civil war most people kept their weapons instead of handing them over..
The syrian invasion happened unofficially in 1975, they were officially asked to help in 1976 which was probably the biggest mistake lebanon ever made. We saw them entering as friends only to find out that they would be the major factor in the war lasting that long. They did help against the palestinians in the beginning only to begin siding with pretty much every side there was only to create more turmoil. They werent with anyone but themselves and they spent the whole time pitting every lebanese against the other.
The christians at the time were fighting against the palestinians. all that is heard about the palestinians is the sabra and chatila massacres. They never mention any massacres they did to us christians because it doesnt matter to the west when the oppressed people are christian.
http://www.gotc.org/black_page/chronology.htm
Thats just a small list of the civilians murdered by the syrians and palestinians.
You can also find pictures(warning some are pretty graphic)
Jumblatt during the war was a puppet of syria, he will suck up to whoever the biggest power broker is to ensure that his tiny druze community gets treated well.