This is a difficult event to evaluate. It comes at a time when the insurgency in Iraq has died down and thus, there is little need to strike at Syria. Of course US-Syrian relations are terrible so this incident does not really change anything. In addition the US has sat on the side lines during the whole Israeli-Syrian peace talks even though both Syria and Turkey have desperately sought the US stamp of approval. The US has little reason to try and destabilize that process with an attack, the Russian resurgence has already done a good job of that, with Syria scurrying back to their old partner. In fact the only country in the region who would be interested in destabilizing Syria is Iran (who views peace talks between Israel and Syria as a bad thing), but we would be drifting into the world of ridicules conspiracy theories to suggest they had anything to do with this event. All this leaves only one conclusion, the US had intelligence that suggested a high value target was in the area, they could not get Syrian government approval to enter the country or did not even try and crossed the boarder to accomplish a task they felt was necessary. This would also be in keeping with the US militaries new position on boarders (best demonstrated by examining recent events in Pakistan and Afghanistan) which is that when terrorists are involved they don't mean anything, which is a fairly pragmatic, albeit unpopular point of view.