Saad al-Hariri, the Lebanese parliamentary majority leader, has returned to his country more than six months after he left because of security worries. An aide said al-Hariri returned to Beirut on Saturday night, three days before Lebanon marked the first anniversary of the assassination of his father, Rafiq al-Hariri, the former prime minister of Lebanon. Al-Hariri left Lebanon in late July and weeks later said a plot to kill him had been uncovered. He spent most of his time in France and in Saudi Arabia, meeting the leaders of both countries. Al-Hariri also held talks last month with George Bush, the US president, in Washington.