REVIVIM JUNCTION— Israel  On a dusty field in Israel’s southern desert, the military is gearing up for the next battle against a familiar foe: Hezbollah guerrillas in Lebanon.As the Syrian civil war intensifies, military planners are growing increasingly jittery that the fighting could spill over into Israel, potentially dragging the Islamic militant group that is allied with President Bashar Assad into the fray. After battling Hezbollah to a stalemate in 2006, the Israeli military says it has learned key lessons and is prepared to inflict heavy damage on the group if fighting begins again.The Israel-Lebanon border has remained largely quiet since that last war. But Hezbollah has since replenished its arsenal and has waged a shadow war with Israel around the world. The fall of the Syrian leader or alternatively an Israel strike against Hezbollah’s other main patron, Iran, could spark another full-fledged war."There is an increase in tension because of Syria,” a senior commander in the military’s northern command said about a possible battle with Hezbollah. The commander, who traveled south to observe Thursday’s exercise here, spoke on condition of anonymity in line with military protocol.In 2006, weeks of Israeli air raids killed more than 1,000 people, including hundreds of Hezbollah fighters, and key infrastructure was destroyed. But the heavy onslaught failed to prevent Hezbollah from firing some 4,000 rockets into Israel, and the fighting ended in a U.N.-brokered truce.While the truce has largely held, Israel says Hezbollah has systematically restocked its arsenal with tens of thousands of even more powerful rockets and missiles capable of striking virtually anywhere in the Jewish state. Israeli military officials frequently say it is only a matter of time before the next war erupts.In the meantime, Israel and Hezbollah have fought a covert war outside the borders of their countries. In 2008, Hezbollah’s top military commander Imad Mughniyeh was killed in a car bomb in the Syrian capital of Damascus, an attack widely thought to be the work of Israeli agents.Hezbollah, for its part, is thought to be responsible for a bus bombing in a Bulgarian resort town last July that killed five Israeli tourists and their Bulgarian driver, as well as failed attempts to bomb Israeli diplomats in Thailand, India and Georgia.Israeli military officials believe that Hezbollah, which is preoccupied with its own domestic problems and the precarious position of its Syrian ally, has no desire to reignite hostilities. But they say the Syrian civil war, as well as Israel’s tensions with Iran, could easily upset the fragile balance.As Assad’s grip on power weakens, Israeli military planners fear that Syria, backed by Hezbollah, might try to open a new front in order to deflect attention.

Israel also fears that sophisticated Syrian weapons, including a chemical arsenal, could be transferred to Hezbollah. Israel has all but confirmed it carried out an airstrike in Syria in January that destroyed a shipment of anti-aircraft missiles allegedly bound to Hezbollah.