On Feb. 14, 2005, a massive bomb killed the former prime minister of Lebanon, Rafik Hariri, my father, along with 22 other Lebanese. The Special Tribunal for Lebanon at The Hague identified five Hezbollah operatives as suspected collaborators in the murder. If proved, that would mean his assassination was carried out by Iran’s allies in Lebanon, who are financed and controlled by the regime in Tehran.

Three years later, in 2008, Hezbollah moved to occupy Beirut, and after many years of promising that its vast, Iranian-supplied arsenal was intended only to protect Lebanon from Israel, turned its weapons against the Lebanese people.

More recently, Hezbollah has prevented Lebanon from electing a new president and has imposed a devastating gridlock on the country’s government in order to blackmail the citizenry into accepting its demands.

Meanwhile, Hezbollah has sent thousands of young Lebanese men to fight and die in Syria to defend the odious regime of Bashar al-Assad, the brutal dictator condemned in the United Nations and around the world for presiding over the deaths of at least a quarter million of his own people. Mr. Assad — with the help of Iran; its Revolutionary Guards and its proxies; Hezbollah and militias in Iraq and Afghanistan — has created the worst refugee problem since World War II, ruthlessly displacing millions of people into neighboring countries and Europe.