Despite its own formidable missile arsenal and its reputation as the region’s leading anti-Israel resistance force, Hezbollah is approaching the Gaza crisis with caution, mindful that any action it takes could backfire at a time when the group faces unprecedented challenges at home.

The military option appears off the table for Hezbollah. If it were to join Gaza’s Hamas miliants in firing rockets at Israel, it would likely raise an outcry from many in Lebanon accusing the Shiite guerrillas of dragging the country into a war with Israel. When Hezbollah sent an Iranian-made reconnaissance drone over Israel last month, the group boasted of its capabilities — but critics in Lebanon slammed it for embarking on a unilateral adventure that could provoke Israel.

Hezbollah is also hamstrung by the civil war in Syria, which has heavily damaged its reputation. Once praised across the Arab world as its champion against Israel, now many — particularly in the region’s Sunni Muslim majority — see it foremost as the backer of Syrian President Bashar Assad in his bloody crackdown on the uprising that erupted against his rule in March 2011.

Anything Hezbollah says against Israel’s campaign will ring hollow for many. Already Syrian regime opponents have drawn parallels between Israel’s bombardment of Gaza and Assad’s crackdown, posting gruesome pictures on social media sites showing dead children in Syria and Gaza.

“Condemning Israeli violence while standing by a Syrian regime that is killing its own people definitely highlights the hypocrisy of Hezbollah’s Syria stance. It will further sink its standing in the Arab street,” said Randa Slim, a research fellow at the New America Foundation in Washington.

Activists say close to 40,000 people have been killed in 20 months of fighting in Syria. The brutal campaign by Assad’s regime against the Sunni-dominated uprising has undermined the so-called “Axis of Resistance” — the anti-Israeli and anti-American alliance of Syria, Iran, Hezbollah and Hamas. Embarrassed by the bloodshed, leaders of Sunni Hamas who had been based in Damascus since the late 1990s broke with Syria, sided with the rebels and left for Egypt and Qatar, though Hamas’ fighters in Gaza have continued to receive weapons from Iran.

Still, Hezbollah has tried to use Israel’s campaign in Gaza — launched in an attempt to stop militant rocket fire — to shift the narrative away from Syria and back to its familiar ground of “resistance.”

Hezbollah leader Sheik Hassan Nasrallah pledged his group’s support for Gaza’s Hamas rulers, insisting it was unaffected by disagreements over the conflict in Syria.

“Iran, Syria and Hezbollah will not abandon Gaza and its people, and just as we were with them over the past several years we will continue to stand by them. This is our religious and moral and humanitarian obligation,” he said in a speech to his supporters Monday night.

But far from his traditionally fiery speeches, the black-turbaned Hezbollah chief appeared subdued and bitter. He even implicitly suggested Hamas was ungrateful for the Iranian and Syrian role in supplying it with the longer-range rockets it has used to target Tel Aviv and Jerusalem, adding a jibe at Egypt for its help to Israelin closing the Gaza Strip.

“Despite the blockade imposed by some Arabs, how did the weapons reach Gaza, how did Fajr 5 missiles reach Gaza? … Who sent them? And who transported them?” he said. “We need to ask who enabled Gaza to stand on its feet today, to fight and make surprises and to shell Tel Aviv and Jerusalem and to fire at planes and battleships.”

He also accused Arabs of a double standard. “The Arabs are sending truckloads and shiploads of weapons to the Syrian opposition, but they do not even dare to send one bullet to Gaza for fear of upsetting Israel and the Americans,” he said.

Founded in 1982 with Iranian support to fight Israel’s invasion of Lebanon, Hezbollah has since grown into one of the most robust, organized and sophisticated resistance groups in the world with a small army of about 6,000 fighters.

In 2000, it succeeded in driving Israeli occupation forces out of south Lebanon following an attrition war that eventually led to the withdrawal. In 2006, the group fought Israel to a standstill, raising the group in the eyes of many in the Arab world to almost iconic status. Hezbollah also gained political power, dominating the current government, which was formed after the group forced the ouster of its Western-backed predecessor.

But at the same time, Hezbollah has come under increasing pressure at home to disarm. Lebanon has become increasingly polarized along multiple lines — Sunnis versus Shiites, the anti-Syrian camp versus the pro-Syrian camp — and pro-Western groups in the country have accused Hezbollah of facilitating political assassinations of anti-Syrian figures in Lebanon.

The uprising in Syria, the main transit point of weapons bought from Iran to Hezbollah, presents the group with its toughest challenge since its inception.

Assad’s fall would be a nightmare scenario for Hezbollah. Any new regime led by the country’s majority Sunni Muslims would likely be hostile to Shiite Muslim Hezbollah. Iran remains the group’s most important patron, but Syria is a crucial supply route. Without it, Hezbollah will struggle to get money and weapons as easily.

Given all the potential dangers, Hezbollah will likely stay on the sidelines of the Hamas-Israel fight, the U.S. security think tank Stratfor said in a report this week. “With Hezbollah uncertain how the Israel-Hamas battle will play out, the group appears to be taking a cautious approach,” it said.

The Texas-based intelligence analysis firm also said it has received indication that Hezbollah has deployed operatives in plainclothes along the border with Israel to monitor the situation and prevent radical Palestinian groups from firing rockets into northern Israel, which would potentially force Hezbollah into a fight if Israelresponded.

A Hezbollah official in south Lebanon confirmed the group was on full alert in case of any Israeli attack in light of the Gaza situation, but denied members were policing the border to prevent attacks on Israel.

“This is a job for the army and United Nations peacekeeper, not Hezbollah,” he said, speaking on condition of anonymity because he was not authorized to discuss security issues.