Syria - Inter Arab Rivalries and the Hezbollah Spark

Hezbollah's victory over Israel in 2006 sparked the fermenting of unrest in Syria. The Gulf Arab regimes did not support Hezbollah and Syria did, Bashar Al Assad called the Gulf Arab leaders "Half Men" for their lack of support, and this lit the fire.
Israel saw the need to undermine the feeding of Hezbollah through Syria. And that explains a lot of what is going on today. Source