Almost as soon as Lebanon's leaders boarded planes for Qatar on Friday for talks to resolve their most dangerous political showdownn since the end of the civil war, the Lebanese took a collective sigh of relief. Not because anyone thinks that peace is about to break out, but because Lebanon is arguably safer as long as most of the top men are out of town. "Don't come back until you've reached an agreement," read signs carried by disabled civil society protesters rallying in wheelchairs along the airport road.Unfortunately for the Lebanese, their leaders are almost certainly coming back soon, and probably without a workable agreement. That's because 18 months into the stalemate between the U.S. and Saudi-backed government on the one hand and the Syrian- and Iranian-supported opposition on the other, the differences between the two camps appear to be irreconcilable for now. Hizballah, the leading party of the opposition, is convinced that the government of Fouad Siniora is carrying out an American-Israeli plan to disarm its military wing. The ruling coalition, for its part, is convinced it is under threat of a military coup planned in Teheran and Damascus.Those tensions came to a head earlier this month, when Hizballah and allied fighters quickly neutralized the militia of parties in the ruling coalition, and ejected them from their political offices and media headquarters, after the government declared its intention to shut down Hizballah's private military telecommunications network. The battle was a clarifying moment for Lebanon, and the picture isn't pretty: It showed that Hizballah — despite years of promising that its weapons were only to fight Israel, and would never be turned on fellow Lebanese — will break that promise in order to maintain its state-within-a-state military infrastructure. The showdown also showed that the U.S.-backed ruling coalition is a government in name only — the national army, for fear of breaking apart on sectarian lines, won't even try and protect the government from Hizballah, while neither the police of the gangs of loyalist gunmen were any match for Hizballah's ruthless efficiency and superior firepower.Still, for all its military supremacy, Hizballah needs a political settlement in order to legitimize its role as a state-within-a-state. It may be the largest Shi'ite political party, but it recognizes that it can't run Lebanon on its own. Governing Lebanon, with its 17 different religious groups and a constitution that divides power among them, is beyond any single party or sect. Fighting Israel is a whole lot easier for Hizballah. And that fact creates leverage for the government, which, despite its military defeat, is refusing to accept Hizballah's political terms — a new government in which Hizballah would have an expanded role and an effective veto over major decisions. The Siniora government is able to refuse a political deal, but not to reverse Hizballah's overwhelming dominance in the balance of power on the ground. That leaves its only option as continued delay, as it cling to the symbols of international legitimacy even though it has little street credibility.The political game is increasingly dangerous for all sides. With a vacuum in government — a new President has yet to be elected — the streets are reasserting themselves. Already the country is dividing up neighborhood by neighborhood, town by town, with gangs forming to protect their turf and screen outsiders. Unable to confront Hizballah directly, Sunni gangs may be tempted to seek revenge on Shi'ite civilians. Al-Qaeda-inspired groups are clamoring to come to Lebanon and kill Shi'ites, just as they have done in Iraq. And if the government continues to refuse its terms, Hizballah may be tempted to send out its troops once again.For now, the barricades are gone and the beaches are open, and Lebanon could have its first normal tourist summer in years. But absent a broad regional settlement that includes a modus vivendi between Washington and Tehran, and peace between Israel and its neighbors, the Lebanese summer is unlikely to last.