Israeli officials recently expressed concern over Syria’s chemical weapons, fearing that they could fall into the hands of Hezbollah fighters who have allied themselves with Assad. Two days ago, Israeli forces struck a target in Syria near the Lebanese border. There were reports that the target was a convoy transporting Russian-made anti-aircraft missiles to Hezbollah. From the AP:

The regional security officials said Israel had been planning in recent days to hit a Syrian shipment of weapons bound for Hezbollah, which is neighboring Lebanon's most powerful military force and committed to Israel's destruction. They said the shipment included sophisticated Russian-made SA-17 anti-aircraft missiles whose acquisition by Hezbollah would be "game-changing" by allowing it to blunt Israel's air power. 

The strike may have halted that transfer.

The Israeli military and a Hezbollah spokesman both declined to comment, and Syria denied the existence of any such shipment.

U.S. officials confirmed the strike, saying it hit a convoy of trucks, but gave no further information.

All officials spoke on condition of anonymity because they were not authorized to brief the media.

In the days since the strike Iran has increased its support for Syria, Israeli warplanes have been flying over Lebanon, Lebanon’s Grand Mufti has criticized the attack, and Lebanese soldiers have been killed along the Syrian border while trying to arrest a fighter linked to a jihadist group that is fighting with Syrian rebels. It should come as no surprise that Syria and Iran have threatened to respond to the Israeli strike. Russian officials have also expressed outrage, saying that the strike violates the United Nations Charter.

The nature of the conflict in Syria means that other countries in the region were almost certainly going to get involved at some point. Turkey has already responded to attacks from Syria, and there have been reports that among the rebels fighting against Assad’s regime are Jordanians, Tunisians, Libyans, and Pakistanis. The conflict’s proximity to Israel as well as Iranian and Russian support for Syria are also factors that contribute to the increased likelihood of the conflict growing beyond Syria’s borders more often.