Where do I begin?

It's all the Syrians fault. That is where I would begin. 15 years of "avoided" occupation plus 15 years of "authorized" occupation, and you expect it all to disappear in a matter of 2 years? Get serious. Syria has managed to plant various groups and factions that operate directly and indirectly under her authority. Only time will tell the extent of this infiltration.

The camp of Nahr el Bared (Reuters)

The recent events between "Fateh Al Islam" and the Lebanese army shows the extent that these groups are being mobilized by Syrian orders. Why now? A wild guess on my side:

"The International Tribunal"

Remember Bashar's threat that he will "Burn Lebanon" if the tribunal is passed. This is the "First Rain" as it seems, a couple of days after the tribunal was put in the hands of the United Nations.

As we say in Lebanon "Allah Yostor".