While the Iranians rightly condemned Saudi Arabia, I find it quite ironic when they represent the murders as a "medieval act of savagery." It's as if the Saudi's, in executing Shiite clerics, held up a mirror to the Iranians in which they saw reflected back their own long-standing and brutal civil and human rights atrocities.
The bigger threat to Lebanese stability is the implosion of Syria, which long played a dominant, sometimes controlling, role in Lebanon. Hezbollah has directly intervened on the side of the Assad regime. The Shia movement's involvement risks bringing the conflict back to Lebanon, as did Hezbollah's costly 2006 war with Israel.