BEIRUT, Lebanon — Lebanon's powerful Hezbollah guerrilla movement _ widely seen as the Arab world's most effective force against Israel _ is a staunch Hamas supporter but has so far held its fire as its Palestinian ally faces down Israel's assault in Gaza.
Hezbollah possesses a formidable arsenal of rockets and missiles that bloodied Israel during a monthlong war between them in 2006, but is constrained by its own domestic political goals and fears of Israeli retaliation.
Once considered as just a fighting force backed by Iran and Syria, Hezbollah has seen its political power in Lebanon grow since 2006. With Israel threatening massive retaliation if Hezbollah renews its rocket bombardments, that influence could come into doubt by Lebanese reluctant to be drawn into another war.
So Hezbollah is instead calling for protests in Lebanon and across the Middle East to pressure Arab governments to act against Israel.
That call hasn't drawn any action for now _ Egypt on Tuesday said it would not end its blockade of Gaza as long as Hamas remains in power there, and no Arab government has offered anything stronger than words and humanitarian assistance in response to Israel's assault.
Hezbollah's leader Hassan Nasrallah drew tens of thousands, waving Palestinian, Hezbollah and Lebanese flags, for a rally Monday in his south Beirut stronghold. He professed that Israel's Gaza offensive will ultimately fail.
Nasrallah put his men on alert in southern Lebanon in case Israel attacks and claimed he was ready to fight back if provoked. He promised not to abandon Hamas. The Islamic Sunni group is also backed by Hezbollah allies Iran and Syria.
But he made no threat to open fire on northern Israel to relieve Gaza _ an act that would certainly provoke another war with Israel.
Hezbollah "cannot afford to enter a full-scale war with Israel, which would be devastating for Lebanon," said Paul Salem, Beirut-based director of the Carnegie Middle East Center, an arm of the Washington-based Carnegie Endowment for International Peace.
The 2006 war was sparked when Hezbollah guerrillas snatched two Israel soldiers from northern Israel. Israel unleashed a massive bombardment of southern Lebanon and other parts of the country and Hezbollah fired thousands of rockets into Israel. The violence devastated much of southern Lebanon, and more than 1,000 Lebanese and about 160 Israelis were killed.
In May, Hezbollah gained significant clout by joining a national unity government with pro-U.S. rivals in Lebanon. The country is now enjoying an unusually long stretch of relative calm and prosperity _ and many Lebanese fear anything that could disturb the stability.
But Hezbollah has also rebuilt its arsenal and claims to possess more than 30,000 rockets, with far greater range, sophistication and firepower than Hamas' mostly primitive rockets.
For its part, Israel has also been enhancing its army's capabilities. Israel's top commander on the border with Lebanon, Maj. Gen. Gadi Eizenkot, warned in October that Israel would reply with "disproportionate force" if Hezbollah attacks again, adding that any village used to fire missiles against the Jewish state will be destroyed.
Hezbollah also has to reckon with Lebanese army and a more robust U.N. peacekeeping force in the south near the border with Israel. Since 2006, thousands of Lebanese troops have deployed along with 13,000 U.N. peacekeepers in a border zone.
For now, Hezbollah's strategy seems to be to mobilize the Arab masses, particularly in Egypt, while counting on Hamas holding out until Israel backs down under outside pressure to end the Gaza offensive.
Hezbollah expert Amal Saad-Ghorayeb describes the conflict as an "existential" one between those opposed to U.S. and Israeli policy _ namely, Hamas, Hezbollah, Syria and Iran _ and the so-called pro-U.S. Arab states.
A Hamas defeat will weaken its backers and "the moderate axis will reign supreme." But if Hamas survives, it would be a major victory for them, said Saad-Ghorayeb, author of the book "Hezbollah: Politics and Religion."
Salem says the Gaza fighting will do little to resolve contentious issues such as West Bank settlements, the fate of Arab east Jerusalem and the Syrian-Israeli conflict.
"In a way this is a war that is not going to solve anything. It will kill hundreds and thousands of people and we still remain where we are," he said.