THE MISSILE

The Fateh-110, or “Conqueror” in Farsi, is a short-range ballistic missile developed by Iran and first put into service in 2002. The Islamic Republic unveiled an upgraded version last year that improved the weapon’s accuracy and increased its range to 185 miles. Iranian Defense Minister Gen. Ahmad Vahidi said at the time that the solid-fueled missile could strike with precision, making it the most accurate weapon of its kind in Iran’s arsenal.

Israel worries the missiles could be transferred to Lebanon’s Hezbollah, providing a major boost to the Shiite militant group’s arsenal. The Fateh-110 is more accurate than anything Hezbollah is currently known to possess. The missile would put almost all of Israel in range, and its precision guidance system poses a threat to Israeli infrastructure and military installations.

— Associated Press

Israel rushed to beef up its rocket defenses on its northern border Sunday to shield against possible retaliation after carrying out two airstrikes in Syria over 48 hours — an unprecedented escalation of Israeli involvement in the Syrian civil war.

Syria and its patron Iran hinted at possible retribution, though the rhetoric in official statements appeared relatively muted.

Despite new concerns about a regional war, Israeli officials signaled they will keep trying to block what they see as an effort by Iran to send sophisticated weapons to Lebanon’s Hezbollah militia ahead of a possible collapse of Syrian President Bashar Assad’s regime.

Israel has repeatedly threatened to intervene in the Syrian civil war to stop the transfer of what it calls “game-changing” weapons to Hezbollah, a Syrian-backed group that battled Israel to a stalemate during a monthlong war in 2006.

Since carrying out a lone airstrike in January that reportedly destroyed a shipment of anti-aircraft missiles headed to Hezbollah, Israel had largely stayed on the sidelines. That changed over the weekend with a pair of airstrikes, including an attack near a sprawling military complex close to the Syrian capital of Damascus early Sunday that set off a series of powerful explosions.

The Israeli government and military refused to comment. But a senior Israeli official said both airstrikes targeted shipments of Fateh-110 missiles bound for Hezbollah. The official spoke on condition of anonymity because he was discussing a covert military operation.

Syria’s government called the attacks a “flagrant violation of international law” that has made the Middle East “more dangerous.” It also claimed the Israeli strikes proved the Jewish state’s links to rebel groups trying to overthrow Assad’s regime.

Syria’s information minister, Omran al-Zoubi, reading a Cabinet statement after an emergency government meeting, said Syria has the right and duty “to defend its people by all available means.”

Israeli defense officials believe Assad has little desire to open a new front with Israel when he is preoccupied with the survival of his regime. More than 70,000 people have been killed since the uprising against Assad erupted in March 2011, and Israeli officials believe it is only a matter of time before Assad is toppled.

Still, Israel seemed to be taking the Syrian threats seriously. Israel’s military deployed two batteries of its Iron Dome rocket defense system to the north of the country Sunday. It described the move as part of “ongoing situational assessments.”

Israel says the Iron Dome shot down hundreds of incoming short-range rockets during eight days of fighting against Hamas militants in the Gaza Strip last November. Hezbollah fired some 4,000 rockets into Israel during the 2006 war, and Israel believes the group now possesses tens of thousands of rockets and missiles.

The Iron Dome deployment followed a surprise Israeli drill last week in which several thousand reservists simulated conflict in the north. In another possible sign of concern, Israel closed the airspace over northern Israel to civilian flights Sunday and tightened security at embassies overseas, Israeli media reported. Israeli officials would not confirm either measure.

Reflecting fears of ordinary Israelis, the country’s postal service, which helps distribute government-issue gas masks, said demand jumped to four times the normal level Sunday.

Israel’s deputy defense minister, Danny Danon, would neither confirm nor deny the airstrikes. He said, however, that Israel “is guarding its interests and will continue to do so in the future.”

“Israel cannot allow weapons, dangerous weapons, to get into the hands of terror organizations,” he told Army Radio.

The attacks pose a dilemma for the embattled Assad regime.

If it fails to respond, it looks weak and opens the door to more airstrikes. But any military retaliation against Israel would risk dragging the Jewish state and its powerful army into a broader conflict. With few exceptions, Israel and Syria have not engaged in direct fighting in roughly 40 years.

Iran condemned the airstrikes, and a senior official hinted at possible retribution from Hezbollah.

Gen. Masoud Jazayeri, assistant to the Iranian chief of staff, told Iran’s state-run Arabic-language Al-Alam TV that Tehran “will not allow the enemy (Israel) to harm the security of the region.”

Iran has provided both financial and military support to Hezbollah for decades and has used Syria as a conduit for both. If Assad were to fall, that pipeline could be cut, dealing a serious blow to Hezbollah’s ability to confront Israel.