The Hezbollah-forced collapse of Lebanon’s government leaves little doubt about the Iranian-sponsored terrorist organization’s responsibility for the 2005 car-bombing assassination of Prime Minister Rafiq Hariri in Beirut. While Hezbollah leader Sheikh Nasrallah’s latest ploy wil not forestall the U.N. Special Tribunal on Lebanon -- set up after the assassination -- from issuing the long-anticipated indictments of those responsible, he’s clearly and perilously not giving up the fight.

In his national address Sunday evening on Hezbollah’s Al-Manar TV, Nasrallah proclaimed that the cabinet ministers associated with the Hezbollah-led parliamentary coalition resigned in order to save Lebanon from its own democratically-elected government.

Showing no shame, Nasrallah vowed that Saad Hariri, the son of the murdered leader, should not be allowed to return to the prime minister’s office, a post he held for the past 14 months. Heading a so-called "national unity government," Hariri, in the interest of fostering political harmony in this severely fragmented country of four million, ironically had allocated one-third of the cabinet seats to Hezbollah allies.

Under Lebanon’s Constitution that gave Nasrallah enormous influence and veto power. -- It only takes a one-third cabinet vote to dismantle the government. But that same constitution also provides that the country’s president must be a Maronite Christian, the prime minster a Sunni and the parliament speaker a Shiite. Depending on negotiations to form a new government, Saad Hariri may still return.

For Nasrallah, it’s been a vain effort to stop the five-year-old U.N. investigation. In recent weeks, Hezbollah stepped up its threats, calling on Saad Hariri to suspend Lebanon’s finanical contributions to the tribunal and to also make clear that indictments would not be honored.

Well, if any Hezbollah officials are indicted, good luck bringing them to justice. Like its Iranian patron, which has perfected defying the U.N. on its nuclear weapons program, Hezbollah has a passion for circumventing international legal sanctions.

Followng the Hezbollah-instigated war with Israel in 2006, the U.N. called for disarming the group and reestablishing the Lebanese government’s control in southern Lebanon. However, massive quantities of arms continued to come across the porous Lebanese-Syrian border unimpeded. Hezbollah is today more powerful than ever, dwarfing Lebanon’s own army, posing threats to Lebanon as well as to Israel.

Similarly, Hezbollah and its Iranian patron have dismissed the “red notices” issued by Interpol, seeking arrests for the 1994 bombing of the AMIA Jewish community center in Buenos Aires. The devastating attack, killing 85 Argentines and wounding hundreds, was an early warning of the collusion between Iran and Hezbollah, and their ability to reach far from the Middle East. To this day, concerns about Hezbollah operatives waiting in the Western hemisphere to be activated cannot be ignored.

The trajectory of Hezbollah’s ascendancy over the past three decades from a terrorist organization to a partner in the government has been stunning, with untold ramifications for Lebanon, its immediate neighbors, the region and beyond. The success of this terrorist organization is due in part to the fractiousness of Lebanese society, which endured a long, costly civil war that formally ended in 1990. But while the internal violence has significantly subsided, the divisions linger as do the underlying threats of renewed conflict.

Bringing down the government without firing a shot has further emboldened Nasrallah. And this political maneuver came just three months after Iranian President Mahmoud Ahmadinejad visited Lebanon, not to meet with Hariri, but to demonstrate public support for Hezbollah and its supporters in the Shiite communities of Beirut and southern Lebanon.

In the weeks ahead Lebanese leaders will have to struggle to negotiate forming a new government at the same time as they grapple with how to respond as a nation to the U.N. tribunal indictments. Both will require the kind of political harmony and cohesiveness that has eluded Lebanon, and that is made all the more difficult by the constant meddling of other countries.

Lebanon has long been the chessboard of international politics. Supporting efforts to re-enforce a stable Lebanon, while keeping at bay Iran and Syria, two countries that also might be implicated in the assassination, must be a top priority for U.S. policy in the Middle East.

Kenneth Bandler is the American Jewish Committee’s director of communications.