One very useful axiom of Middle East politics is "Someone always does something stupid." Today's example is the news that Syria transferred scud missiles to Hizbullah sometime in the past two months. These missiles, unlike the smaller Katyusha rockets, are capable of hitting most places in Israel, and would do considerably more damage. Wars in the Middle East tend to start when there is a rapid flux in the balance of power at the time. This event qualifies with room to spare. The situation is extremely perilous between Hizbullah and Israel right now.
But what significantly degrades the risk are statements from Hizbullah that Israel is overreacting, and statements from Syria denying the transfer in the first place. If Hizbullah were interested in posturing, they would invite Israel's reaction. A nervous Israel is a secure Hizbullah. The fact that they seem to be downplaying the incident illustrates that they were caught a bit off guard by the announcement, and are likely not looking for a conflict with Israel.
Syria's decision to transfer the missiles has got to be one of the poorest foreign policy decisions in the Middle East of 2010. The US was set to approve the first US Ambassador to Syria in years, and Syria is at increasing risk of being caught between a military engagement between Israel and Iran. Evidently the deal was supposed to be secret, but even so, it was foolish for Syria to assume that giving Hizbullah scuds would go unnoticed.
In the coming days, Hizbullah has to be very careful to posture itself in a position of strength, but not so much that Israel percieves an innocent threat. With political interests in Beirut, it is not in Hizbullah's interest to start a new war with Israel.
This of course assumes that Israel's response will be tempered as well. So far Ehud Barak has expressed only "concern" and Israel has far more pressing interests than getting into a war in Lebanon, especially considering their 2006 experience. And while the U.S. would likely support Israel in a hypothetical war, Netanyahu can't be sure, and a conflict with Hizbullah is not the place to find out.
Most likely, the general understanding that a war is bad for all sides will prevent this from going further in a military sense. But then again, it's the Middle East. Someone always does something stupid.