Hezbollah is a Shiite Muslim political group with a militant wing the United States defines as a terrorist organization. The group, which is active in Lebanon, is a major provider of social services, operating schools, hospitals, and agricultural services for thousands of Lebanese Shiites. Hezbollah's political standing was bolstered after a wave of violence in May 2008 prompted Lebanon's lawmakers to compromise with the militant group. In August 2008, the country's parliament approved a national unity cabinet, giving Hezbollah and its allies veto power with eleven of thirty cabinet seats. Early results from June 2009 parliamentary elections showed Hezbollah losing to Lebanon's ruling, pro-Western "March 14" coalition. Hezbollah also operates the al-Manar satellite television channel and broadcast station.

Hezbollah was founded in 1982 in response to the Israeli invasion of Lebanon, and subsumed members of the 1980s coalition of groups known as Islamic Jihad. It has close links to Iran and Syria.

Sheikh Mohammed Hussein Fadlallah is considered the group’s spiritual leader.

Hassan Nasrallah is Hezbollah’s senior political leader. Nasrallah was originally a military commander, but his military and religious credentials—he studied in centers of Shiite theology in Iran and Iraq—quickly elevated him to leadership within the group. Experts say he took advantage of rivalries within Hezbollah and the favor of the head of Iran’s theocratic government, Ayatollah Ruhollah Musavi Khomeini, to become the group’s secretary general in 1992, a position he still holds.

For over twenty years, Imad Fayez Mugniyah was considered the key planner of Hezbollah’s worldwide terrorist operations. During the Lebanese civil war in the 1970s, experts say Mugniyah trained with al-Fatah. When the Palestine Liberation Organization and al-Fatah were expelled from Lebanon by Israeli forces in 1982, Mugniyah joined the newly formed Hezbollah and quickly rose to a senior position in the organization. On Februrary 13, 2008, Mugniyah was killed in a car bombing in Damascus. Hezbollah officials accused Israel of launching the attacks that killed him, but the Israeli government has denied involvement.

Its base is in Lebanon's Shiite-dominated areas, including parts of Beirut, southern Lebanon, and the Bekaa Valley. In addition, U.S. intelligence reports say that Hezbollah cells operate in Europe, Africa, South America, and North America.

Despite Israel's 2000 withdrawal from Lebanon, Hezbollah continued to periodically shell Israeli forces in the disputed Shebaa Farms border zone. Periodic conflict between the group and Israel erupted into full-scale war during the summer of 2006. A UN-brokered cease-fire was formalized on August 14, 2006, ending the five-week conflict, but not before more than one thousand people were killed and hundreds of thousands were forced to flee.

Its core consists of several thousand militants and activists, the U.S. government estimates.

Hezbollah and its affiliates have planned or been linked to a lengthy series of terrorist attacks against the United States, Israel, and other Western targets. These attacks include:

• a series of kidnappings of Westerners in Lebanon, including several Americans, in the 1980s;
• the suicide truck bombings that killed more than 200 U.S. Marines at their barracks in Beirut, Lebanon, in 1983;
• the 1985 hijacking of TWA flight 847, which featured the famous footage of the plane’s pilot leaning out of the cockpit with a gun to his head;
• two major 1990s attacks on Jewish targets in Argentina—the 1992 bombing of the Israeli Embassy (killing twenty-nine) and the 1994 bombing of a Jewish community center (killing ninety-five).
• a July 2006 raid on a border post in northern Israel in which two Israeli soldiers were taken captive. The abductions sparked an Israeli military campaign against Lebanon to which Hezbollah responded by firing rockets across the Lebanese border into Israel.

Yes. After the 2005 elections, Hezbollah won fourteen seats in the 128-member Lebanese Parliament. Its political ascendancy has accelerated since the group's May 2008 takeover of West Beirut, which followed a government-ordered shutdown of Hezbollah's communications network. In an Arab-brokered deal to end the fighting, Hezbollah was granted veto power in Lebanon's parliament, and now controls eleven of thirty seats in the cabinet. Despite the apparent political strengthening, however, some experts say Hezbollah's use of force in the West Beirut showdown—Hezbollah had said it would never turn its weapons on Lebanese civilians—has eroded the group's credibility. In a May 2008 report, the International Crisis Group warned that a line had been crossed that would likely deepen the already tenuous sectarian tensions among Lebanon's ruling and opposition parties.