The Obama administration keeps warning about the internationalization of the Syrian conflict. But it keeps predictably mum about being specific. For good reasons - because the side it supports is the main one involved in this internationalization.
We had the patriots in Turkey because of a few shells that fell on the wrong side of the border, and now occassionally shells are falling in Lebanon. But that is about Assad's part. But consider the other side:
Lebanon was the first country destabilized. From the early stages of the uprising Lebanon was a major supplier of arms and support for the uprising in Homs, Qusair and other cities in the region - support that was funded by Saudi Arabia and organized by Lebanon's Sunni controlled secret services. This soon led to tensions in Tripoli. The tensions only increased when it became clear that Saudi Arabia intends to target Hezbollah next when it has finished with Assad.
Next there was Jordan. Already destabilized by the return of Jordanian Jihadi's fighting in Syria the problem was worsened because the Gulf States stopped the financial support they used to give Jordan. Recently it became clear why: when Jordan allowed its territory as a base for massive support for the Syrian uprising the financial support was resumed. But it may be only a matter of time before the Gulf States order their Brotherhood minions to organize an "Arab Spring" in Jordan too.
Then there is Iraq where the tensions between Sunni and Shiites are increasing. Although prime minister has followed a rather confrontational policies this doesn't explain the systematic nature of the Sunni protests. The daily protests point to a solid organization and it is generally assumed that Saudi Arabia is organizing and financing this uprising.