NEWYou can now listen to Fox News articles!

Editor's note: The following column was first published in City Journal

Since Hamas’s barbaric attack on Israel, Hassan Nasrallah, the long-standing head of Hezbollah, Iran’s terrorist proxy in Lebanon and the country’s de facto ruler, has been uncharacteristically quiet. While Iran has warned that it will respond if Israel invades Gaza and kills Palestinians, no such threat has come from Nasrallah. His silence has intensified a debate among Middle East analysts about whether Hezbollah, and, more precisely, Iran plan to open a second front and escalate the conflict when Israel launches its massive ground invasion of Gaza to decapitate the leadership of Hamas and destroy its capability ever to harm Israelis again.

While Hezbollah and its Palestinian terrorist allies in Lebanon have engaged in limited clashes each day along the Israeli-Lebanese border and fired rockets at northern Israeli military targets, its units have not yet launched massive numbers of missiles and rockets at Israeli civilians and infrastructure from its arsenal of what is estimated to be substantially more than 100,000 rockets and missiles. Nor have its special forces infiltrated Israel. It has yet to call up its reserves, or evacuate the southern suburbs of Beirut, steps it would normally take to prepare for war.

"Nasrallah’s silence and the limited hostilities at the border suggest that Hezbollah—and Iran—have not yet decided how deeply to intervene in the conflict," said Hanin Ghaddar, the author of Hezbollahland and an expert on the group at the Washington Institute for Near East Policy.

ISRAELI OFFICIAL PREDICTS US 'INVOLVEMENT' IF IRAN, HEZBOLLAH JOIN FIGHTING WITH HAMAS

Nasrallah is not usually so diffident. Last February, as hundreds of thousands of Israelis poured into the streets to protest Prime Minister Benjamin Netanyahu’s effort to reduce radically the power of Israel’s independent judiciary, Nasrallah was gloating. In a televised speech from his Lebanese bunker, he quoted Israeli president Isaac Herzog’s warning that compromise among Israel’s political factions was essential if Israel was to avoid tearing itself apart. Noting that neither of the two previous Jewish states in the region had lasted more than 75 years, he said that, "God willing," the third Jewish state, too, would "not reach its 80th birthday."

Since his ascent in 1992 as leader of Lebanon’s most violent militant Shiite Muslim terrorist group and Iran’s most dangerous proxy, Nasrallah has done his best to achieve that goal. A careful student of Israeli internal affairs, he has long celebrated its divisions, attacked what he perceived to be its moments of greatest vulnerability, and encouraged other Muslim militants to annihilate the Jewish state.

HEZBOLLAH TAKES RESPONSIBILITY FOR ATTACKS ON ISRAELI MILITARY POSTS ALONG LEBANON BORDER

But Iran and Hezbollah, the jewel in its terrorist crown, may hesitate to open a second front for several reasons. First, says Peter Berkowitz, a fellow at the Hoover Institute  who worked in former President Trump’s State Department, is President Biden’s strong support of Israel and its right to respond to Hamas’s barbaric slaughter of 1,400 Israelis and seizure of 200 hostages, some of them American. That rhetorical support has been reinforced by the president’s decision to send two carrier strike groups to the eastern Mediterranean as well as a battalion of Marines who were training in Kuwait to deter "regional" actors seeking to widen the war. "This sends a strong message to Iran," Berkowitz said. "Don’t escalate."

Iran may also be hesitant to expand the conflict and risk what some analysts see as the benefits it has already gained from the Hamas–Israeli war. Most important is temporarily disrupting American-backed diplomacy between Saudi Arabia and Israel aimed at Saudi-Israeli recognition. Iran was surely alarmed by Saudi Crown Prince Mohammed bin Salman’s statement to Fox News last month that talk of normalization was "for the first time, real" and that "every day we get closer" to a deal. But after Hamas’s invasion and Israel’s initial bombing of Gaza in response to Hamas’s attack, Riyadh issued a statement denouncing the "displacement of Palestinians" within Gaza and Israel’s attacks on "defenseless civilians," its strongest language to date criticizing Israel.

LIVE UPDATES: ISRAEL AT WAR WITH HAMAS 

Hamas’s attacks have also succeeded in exposing Israel’s weakness: its gross failure of intelligence and preparedness. Exploding the myth of Israeli invincibility has shifted the political narrative away from gradual acceptance of Israel’s right to exist in the region to a re-elevation of the Palestinian cause. "Hamas has succeeded in bringing the Palestinians and their suffering back to the Arab street," said Ghaddar.

In addition, the Israel–Hamas crisis has deflected attention at least temporarily from Iran’s use of proxies to strike America’s allies in the region and from its own nuclear program, especially its repeated violations of the agreement it made with former President Obama aimed at slowing Teheran’s quest for a bomb. After former President Trump unilaterally abandoned the nuclear agreement, Iran has repeatedly ignored its nuclear pledges to Washington and the UN. An escalation of the conflict might give Israel and the U.S. an opportunity to do more to stop Iran’s long-standing quest for the type of nuclear capability that Israel alone in the region possesses.

CLICK HERE FOR MORE FOX NEWS OPINION

Hezbollah, too, has its own reasons for fearing an escalation of the conflict. Nasrallah undoubtedly fears losing the military presence it has steadily built up since its last major clash with Israel in 2006. During that conflict, which Hezbollah provoked by killing three and kidnapping two Israeli soldiers, Israel bombed the homes and offices of Hezbollah’s leaders in Beirut’s southern suburbs and decimated the country’s infrastructure. Nasrallah subsequently expressed regret for the war, which the Lebanese blamed on his Party of God, saying that he never imagined that the capture of two Israeli soldiers would result in a war "of this magnitude." Dragging Lebanon into yet another war with Israel would provoke strong resentment from the Lebanese and further endanger Hezbollah’s hold on power in the country, since the Lebanese economy is already reeling.

However, the decision to widen the Israel–Hamas war will not be made by Hezbollah in Lebanon but by the mullahs in Teheran. Massive numbers of Palestinian deaths in an Israeli response to Hamas could prompt Iran to shift its political calculations. And Teheran could always miscalculate, a tendency well known in the Middle East. Though both Israel and the U.S. have said they have not yet found direct evidence that Iran directed Hamas’s savage attack, Hamas and perhaps Iran itself have already made two such errors. First, Hamas assumed that Israel would not launch a major attack on Gaza if it meant risking the lives of Israeli hostages. And second, the militants who designed and ordered the strike apparently did not believe that America would wholeheartedly back its Jewish ally without restrictions.

Even after Biden’s strong expression of support for Israel’s right to respond, Teheran may well conclude that the presence of the U.S. carriers near Lebanon is mere military posturing—that Biden, given his record to date, is unlikely to use military force. And who could blame Teheran for assuming that Biden is bluffing? 

CLICK HERE TO GET THE FOX NEWS APP

As the Wall Street Journal noted in an editorial Sunday, the U.S. has responded militarily to only four of 83 attacks by Iran’s proxies. Biden’s botched, humiliating withdrawal of American forces from Afghanistan further reinforced the impression among America’s enemies and rivals that the United States has tired of defending its allies and democracy abroad and lacks the political will to engage in such conflicts.

"This is an important test of the Biden administration’s resolve," said Berkowitz. "It’s not just Israel, but America that needs to restore confidence in its deterrence capability."

CLICK HERE TO READ MORE FROM JUDITH MILLER