BEIRUT: A massive military strike by the United States and its Western allies on Syria aimed at changing the balance of power in the country will likely trigger a swift intervention by Hezbollah, political analysts and sources close to the group said Tuesday.

Hezbollah’s response will likely involve the firing of rockets into Israel, igniting the dormant front in south Lebanon, they added.

However, analysts and experts predicted a limited U.S.-led military operation against sites in Syria suspected of stockpiling chemical arms or materials.

A senior source close to Hezbollah told The Daily Star the party was unlikely to retaliate in case the U.S. and its Western allies carried out a punitive operation against Lebanon’s neighbor.

But analysts warned that if the Western attack on Syria over its alleged use of chemical weapons against civilians was aimed at striking the Syrian army or toppling the regime of President Bashar Assad, this would prompt a retaliation from Iran and Hezbollah against Israel.

“In the event of a qualitative [Western military] strike that aims to change the balance of power in Syria, Hezbollah will fight on various fronts,” the senior source said.

“A large-scale Western strike on Syria will plunge Lebanon virtually and immediately into the inferno of a war with Israel,” the source said, clearly referring to the possibility of Hezbollah firing rockets into Israel.

“However, if the Western attack is limited to certain targets in Syria, then, Hezbollah will not intervene,” the source added.

Clouds of war are gathering over Syria amid signs that Western powers could attack the strife-torn country within days.

U.S. Defense Secretary Chuck Hagel said U.S. forces in the region were “ready to go,” as Washington and its European and Middle Eastern partners honed plans to punish Assad for a chemical attack last week that killed hundreds of civilians in eastern Ghouta outside Damascus.

Washington said it already held Assad responsible for a “moral obscenity” and U.S. President Barack Obama would hold him accountable for it.

The Syrian government has denied using chemical weapons.

“I believe that if the [Western] strike is limited to one or two military targets in Syria, I doubt there will be any military reaction from Syria, Hezbollah, or Iran,” Abdallah Bou Habib, Lebanon’s former ambassador to the United States, told The Daily Star.

“The United States does not want a change in the regime in Syria like what happened in Iraq or Libya. They prefer an orderly political transition in Syria that would keep the military and the administrative establishment somewhat intact,” said Bou Habib, also the director of the Issam Fares Center for Lebanon, a Beirut-based think tank.“These goals in Syria will not allow for a long or wide war. Which means that a possible retaliation from Syria, Iran or Hezbollah is highly unlikely,” he added. “Given these goals, the U.S. is highly unlikely to launch a large-scale attack on Syria.”

However, in the event of a massive Western military assault on Syria, Bou Habib said that retaliation by Iran and Hezbollah would become highly possible.

“While Iran will attack U.S. and Gulf states’ [interests] in the region, Hezbollah will ignite the southern front by firing rockets into Israel,” he said.

Hisham Jaber, a retired Lebanese Army general, said he expected a limited military operation against Syria, though he added that no final decision had been made yet in this regard.

“The Americans have a bank of military targets, between 150 to 200 targets to strike in Syria. These include air defense bases, military airports, missile sites, the air bases command and the military command and control headquarters,” Jaber told The Daily Star.

He ruled out the possibility of airstrikes against military targets in Syria.

“I expect a sea strike operation whereby the 6th Fleet in the Mediterranean will unleash Cruise and Tomahawk missiles at the set targets in Syria,” said Jaber, also the director of the Beirut-based think tank, the Middle East Center for Political Studies and Research.

Like other analysts, Jaber said Iran and Hezbollah were unlikely to retaliate for a limited Western assault on Syria.

“But if Syria for some reason responded by firing rockets into Israel, then Hezbollah would feel free to launch rockets on the Jewish state, in a development that would spark a regional war,” he said.

Hilal Khashan, a professor of political science at the American University of Beirut, said the decision for a limited attack on Syria had been made and it would take place within a few days.

He ruled out the possibility of airstrikes, saying military targets in Syria would be attacked with Tomahawk missiles from U.S. warships in the Mediterranean.

“Tomahawk missiles will target, among other things, the location of the 4th Division in Damascus,” Khashan told The Daily Star, referring to the elite military division commanded by Maher Assad, brother of the Syrian president. “The aim is to punish the regime in Damascus for the alleged chemical attack on Ghouta,” he added.

Khashan said the Western strike might also target Hezbollah positions in Syria after the Syrian opposition had provided U.S. Intelligence with maps about the party’s deployment in Syria.

He did not expect Hezbollah or Iran to retaliate whether the attack on Syria was limited or massive. “ Hezbollah will not react in the south against Israel,” Khashan said. “In the event of a large-scale attack on Syria, neither Iran, nor Hezbollah will do anything except pep talk,” he added.

However, Khashan said there was a possibility that Iran might ask Hezbollah to take Western hostages in Lebanon in the event of a massive Western military strike.

But Talal Atrissi, an expert on Iran and Middle East affairs, disagreed with Khashan, predicting a retaliation from Tehran and Hezbollah against Israel if the Western assault was aimed at toppling the Assad regime.

He said he would expect a limited military strike to target “sites allegedly stockpiling chemical materials” in Syria rather than the Syrian army’s positions.

“There will be no response from Iran or Hezbollah if the [Western] attack targets only chemical plants or sites storing chemical materials,” Atrissi, a lecturer at the state-run Lebanese University, told The Daily Star.

“But if the Assad regime or the Syrian army is struck, this would expand the battle, opening the door to all eventualities and triggering a response from Iran and Hezbollah against Israel,” he said.

Atrissi added that the declared position of Iran and Hezbollah, key allies of the Assad regime, is to prevent the regime’s downfall. While Iran is a strategic ally of the Syrian regime, Hezbollah has sent fighters to join Assad’s forces in the war against armed rebels seeking to topple the regime.

Both Jaber and Khashan said the Western military strike was aimed at setting the stage for a political settlement to end two and a half years of bloody conflict in Syria that has killed more than 100,000 people.

“The Americans remain committed to a political solution to the Syrian conflict,” Khashan said. “That’s the reason the attack will be limited.”

Jaber, the retired Army general, spoke of what he called “a tacit agreement” between the U.S. and Russia over “a limited military operation that does not seek to topple the regime or destroy the Syrian army.”

“The aim of this operation is to achieve a breakthrough in the stalemate in the Syrian conflict in order to pave the way for peace negotiations,” Jaber said. “The operation is basically aimed at creating a military balance between the regime and the opposition in order to propel the two sides to the negotiation table,” he added.