Why the Lebanese government collapsed, and why you should care.

BEIRUT—On Wednesday, Hezbollah and its allies abruptly withdrew from the Lebanese Cabinet, forcing the collapse of Prime Minister Saad Hariri's government just moments after he finished meeting with President Barack Obama in Washington.

What may seem like mere parliamentary maneuvering in a country about the size and population of Connecticut was actually the climax of a yearslong drama rife with murder, international conspiracy, espionage, backstabbing, and whisper campaigns.

The string of interconnected developments began in February 2005 with the assassination of former Prime Minister Rafik Hariri. His murder set off a chain reaction that started with Syria pulling out of Lebanon under massive international and domestic pressure and resulted in the establishment of the Special Tribunal for Lebanon, a U.N. Security Council-backed investigation into Hariri's murder.

Fast-forward to November 2009. Saad Hariri—Rafik Hariri's son—formed a "national unity" Cabinet after five months of wrangling between his side, the March 14 coalition, and the opposition March 8 coalition, led by Hezbollah. Things were looking up.

So why did Hezbollah and its allies suddenly decide to pull out of the Cabinet? It's all about the Special Tribunal for Lebanon.

Before the dust from the Feb. 14, 2005, car bomb that killed Rafik Hariri had even settled, fingers of blame pointed at Syria. Back then, Syria was still occupying Lebanon and was allegedly behind the assassination of several Lebanese politicians and journalists critical of the regime. Rafik Hariri had resigned months earlier to protest increased Syrian meddling, so it was easy to believe that Syria would take him out. Who else would have the sophistication or motive to carry out such an attack, which would have required smuggling more than 1,000 kilos of TNT into the country? The notion of Hariri's murder being a Syrian operation gained wide currency and held sway for years.

But by mid-2009, the foundation under the Syria-did-it narrative began to crumble. In May of that year, German newspaper Der Spiegel published an articleclaiming that the special tribunal was preparing to indict members of Hezbollah for Hariri's assassination; Hezbollah—not Syria—was responsible. The article came out of left field and fell out of the news because of the Lebanese parliamentary elections that month and headline-grabbing uprisings in Iran. As 2009 turned into 2010, however, Hezbollah's verbal attacks on the tribunal mounted, and rumors about the pending indictment persisted.

Any confusion about Hezbollah's position was put to rest last July when Hezbollah leader Hassan Nasrallah announced that he considered the tribunal an Israeli-U.S. plot to undermine the party and called on the government to pre-emptively disavow its findings, whatever they might be. In August, Hezbollah showed Israeli drone video footage that it said proved Israel had been monitoring the movements of Rafik Hariri, adding one more layer of possible conspiracy to the investigation. In October, it called on all Lebanese to boycott the findings of the tribunal.

In November 2010, the Canadian Broadcasting Corp. published an investigation that reached precisely the same conclusions as Der Spiegel's. But unlike the Germanreport, the Canadians conducted a parallel investigation using the same data that the U.N. tribunal had at its disposal. Its conclusion was the same: Hezbollah operatives had carried out the assassination.

By then, the predominant narrative had changed from "maybe Hezbollah did it" to "what will Hezbollah do when they are indicted?" and "will the Hariri government reject the tribunal's findings in order to appease Hezbollah and preserve Lebanon's stability?"

Prime Minister Saad Hariri couldn't realistically disavow the Special Tribunal for Lebanon without alienating the Sunnis and anti-Syrian coalition he represents or appearing to be a total wimp—after all, he is the dead guy's son.

So Hariri did not listen to Hezbollah's demands, and the "unity" Cabinet sessions grew more fractious until it eventually stopped meeting—the last time the Cabinet convened was Dec. 15, 2010.