Lebanon is an inherently unstable post-colonial entity, created by France by spliting it off from Syria. But the Lebanese have a very strong sense of belonging to their land, and it it is left to them, there will not be another civil war. It does not help that their PM is a perpetual adolescent with an infatuated sense of himself. But that alone, without the interference of the US and Israel, will not start a civil war.
Yemeni ISIS affiliate claims responsibility for Sanaa mosque bombing (Reuters)
from the article: Hezbollah ministers quit over Hariri probe, toppling Lebanon government