There aren't a lot of opportunities to celebrate national unity in Lebanon, a famously fragile and fractious country. But the five Lebanese militants who arrived home Wednesday in an exchange of prisoners and dead soldiers with Israel returned to a country that seemed momentarily united in victory. The Lebanese government declared a national holiday, and almost the entire Lebanese Cabinet — politicians who are more often plotting one another's demise than appearing together in public — received the new national heroes at Beirut airport with flowers, rice, pomp and circumstance.The contrast with the mood in Israel could hardly have been greater. The very fact that the Israeli government had to barter for the return of two soldiers captured in July 2006 by Hizballah was disappointing enough. The Israeli government had launched a 33-day war to regain its lost boys and destroy the Shi'ite militia but failed on both counts. Moreover, the fact that the two soldiers were returned in black coffins left many Israelis bitter about the price paid by their government: the release of five dangerous militants and the return of the remains of 185 others.But for all the group-hugging in Lebanon, the real winner of the day was Hizballah leader Hassan Nasrallah, who had orchestrated the trade. He claimed the lopsided deal as legitimacy for both his decision to capture those two Israeli soldiers in the first place and his wider strategy of armed confrontation with Israel. For almost 60 years, Arabs facing Israel have had to choose between defeat and peace, but now, according to Nasrallah, the success of Hizballah's asymmetrical warfare has offered a model for all the movements in the Middle East dedicated to destroying Israel. "The essence of the region is the resistance," he said in a rare appearance to welcome the returning prisoners.But not everyone agrees that Hizballah's gains were worth the price paid by Lebanon. A few anti-Hizballah media outlets pointed out that the true cost of the prisoner swap should include destruction wrought by the July war: 1,200 people killed, 400,000 wounded, 1 million displaced and $15 billion in economic damage. Yet, after more than 18 months of internal political stuggles that culminated in a brief armed takeover of Beirut by Hizballah last May, the group has for now effectively ended all debate over its continued bearing of arms. It has secured a veto power in the Cabinet and a sympathetic new President who just announced that, from now on, Hizballah would become part of Lebanon's national defense strategy.That strategy could backfire. By embracing Hizballah's right to bear arms, the Lebanese government is now defying the U.N. resolutions that require its disarmament. And, as destructive as it was, Israel's bombardment of Lebanon in 2006 was largely limited to Hizballah strongholds in the capital and in the south. But in any future confrontation, Israel may use less restraint — and another war could be Lebanon's last.Hizballah seems determined to resolve the rest of its outstanding disagreements with Israel — for example, Shebba Farms and other territory still occupied by Israel but claimed by Lebanon — in a manner similar to how it settled the prisoner issue: guerrilla operations, followed by indirect negotiations. But Israel is now unlikely to make the same kind of deal with a group that sees every negotiation as a step on the road to "liberating" Jerusalem. In that light, the prisoner exchange on July 16 isn't a promising first step toward ending hostilities between Israel and Lebanon, but instead the opening of an unstable new phase in the Arab-Israeli conflict, in which there is no system in place to prevent small outbursts from turning into big wars.