No one in Lebanon seems to know who invited Iranian President Mahmoud Ahmadinejad to Beirut for a two-day “official visit” -- his first since assuming office in Teheran five years ago. No Lebanese official has claimed credit for a trip that Israel and the U.S. have condemned as “provocative.” But it’s shaping up as a potential powder keg and a huge political embarrassment for Lebanon whose reverberations are being felt in many capitals, not just in the Middle East.

Ahmadinejad lost no time in thanking the cheering throngs who lined the streets and pelted his armored car with rice and flowers. These were the tens of thousands of supporters of Hezbollah, Iran’s Shiite Muslim ally in Lebanon which the U.S. and Israel have branded a terrorist organization, despite its participation in Lebanon’s fragile government. Enthusiastic Hezbollahis painted their faces with Iranian flags and hoisted posters featuring Ahmadinejad’s face in a giant red heart to proclaim their “love” for Iran’s unpopular, polarizing president, welcoming him to their capital. He felt “at home” in Lebanon, Ahmadinejad declared. “We are two peoples that love each other. We have joint interests.”

Lebanon’s other political leaders, however, undoubtedly don’t share the love. Consider what the country's Prime Minister Saad Hariri, a Sunni Muslim, must have been thinking Wednesday as he welcomed the man whose country is indirectly responsible for having killed his father, former Prime Minister Rafik Hariri. 

His father’s brazen 2005 murder in a suicide bomb attack in the heart of downtown Beirut sparked massive protests throughout Lebanon. This so-called “Cedar Revolution” succeeded in forcing Syria, Iran’s neighbor and main Sunni Muslim ally, to withdraw the 14,000 “peace-keeping” forces it had been keeping in Lebanon since the end of that country’s bloody civil war in 1990.

But Syria has steadily rebuilt its influence in Lebanon, and Lebanon's Prime Minister Hariri is turning out to be anything but his father’s son. 

Smadar Perry, who covers Arab affairs for the Israeli paper Yediot Ahronot, laments that the young Hariri “no longer dreams of avenging his father’s assassination.” “Spinelessly, he met with Hezbollah leader Hassan Nasrallah (his father’s executioner) and [Syrian President] Bashar Assad (the assassination’s mastermind)” to curry Iranian and Syrian favor. “The only thing he cares about is survival,” she wrote earlier this week. This weakness could prove deadly to prospects for an independent Lebanon.

A special United Nations panel (called the STL, or Special Tribunal for Lebanon) is reportedly on the verge of indicting officials of Hezbollah, which Iran has sponsored, trained and supported since its inception in the wake of Israel’s 1982 invasion of Lebanon, for Hariri’s murder. In an analysis published earlier this week by the Washington Institute for Near East Policy, Ash Jain and Andrew J. Tabler argue that a key goal of Ahmadinejad’s trip is to pressure Lebanon's Prime Minister Hariri and his Lebanese and Western allies into ending their support for the tribunal, which Lebanon has been financing.

Ahmadinejad’s second goal is to build support among the Muslim Arab masses by putting additional pressure on the American-sponsored, now-stalled Arab-Israeli peace talks. On Thursday, the Iranian president is scheduled to tour Bint Jbeil and Qana -- two towns in southern Lebanon on Israel’s border that were badly damaged in previous rounds of fighting between Hezbollah and Israel which Iranian money has helped rebuild. Ahmedinejad clearly intends to throw an actual or rhetorical rock across the border, taunting the Israelis to dare to strike back. 

Israeli officials say that Hezbollah has replenished its conventional arsenal with some 40,000 rockets and missiles, over twice what it had prior to their last war. It has also trained thousands of recruits on new battle tactics in preparation for another war that both Lebanon and Israel increasingly see as inevitable.

In the Christian Science Monitor, Nicholas Blanford, the author of “Killing Mr. Lebanon,” about the Hariri assassination, notes that while this is the Iranian president’s first official visit to Lebanon, Ahmadinejad has visited southern Lebanon before. More than two decades ago, he came to the Bekaa Valley as an officer in the Iranian Revolutionary Guards Corps to help train the Lebanese Shiites who became the nascent Hezbollah.

Hezbollah was young then, and far less dangerous. Its leader, Hassan Nasrallah, was giving speeches declaring that “Lebanon should not be an Islamic republic on its own, but rather, part of the Greater Islamic Republic, governed by the Master of Time [the Mahdi], and his rightful deputy, the Jurisprudent Ruler, Imam Khomeini,” according to a speech published today by MEMRI. Today, he is a self-styled Lebanese patriot, and Hezbollah is not only part of the Lebanese government, capable of bringing it down at will, but also what Blanford calls the “most effective non-state military force in the world.”

But “as an asymmetrical warrior,” writes Lee Smith in the online magazine, Tablet, “Nasrallah understands that even his most capable guerrilla units are no match for Israel.” So he is waging war against “the Jewish state’s center of gravity—public opinion.” Ahmadinejad’s threats to wipe Israel off the map and similar vows by his Lebanese creation, Hassan Nasrallah, play well among Arabs, Shiite and Sunni alike. “By continuing the fight to liberate Jerusalem,” concludes Smith, author of “The Strongest Horse,” Teheran has “picked up the banner of Arab nationalism that the Sunni Arab regimes had tossed by the wayside. Here was another reason for the Arab masses to despise their cruel and now obviously cowardly rulers—and admire a Shia and Persian power they might otherwise fear and detest.”

Small wonder that both Israel and the U.S. are worried about this trip.

Judith Miller is a writer, Manhattan Institute Scholar and Fox News contributor.

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Judith Miller, a Fox News contributor, is an award-winning writer and author, and an adjunct fellow at the Manhattan Institute. She spent 85 days in jail in the Alexandria Detention Center in Virginia in 2005 to protect confidential sources.