BEIRUT -- Twenty years ago in April, a car bomb leveled the US Embassy here; six months later a truckload of explosives was detonated at a US Marine barracks, killing 241 servicemen. The reverberations of those suicide attacks in 1983 are still being felt.
Today the 19-year-old soldier on duty at Beirut airport's Parking Lot C shrugs indifferently when told that this was where the doomed barracks stood. He wasn't even born when the bomb went off on Oct. 23, 1983. For many like him, it's a distant memory, one of scores of atrocities committed during Lebanon's 1975-1990 civil war.
But for Washington it was a watershed. It ultimately drove the US military out of Lebanon. A decade later American forces pulled out of Somalia, their mission again wrecked by violence. Today, as US casualties mount in Iraq, some are asking whether the United States will walk away again.
No way, insists President Bush. "The terrorists have cited the examples of Beirut and Somalia, claiming that if you inflict harm on Americans we will run from a challenge," he said recently. "In this they are mistaken."
Nobody professes to know for sure just who was behind the bombings of 1983.
They were claimed by Islamic Jihad, a shadowy group believed made up of Shi'ites loyal to Iran's late Ayatollah Ruhollah Khomeini. It was generally thought to be the military arm of Hezbollah. Hezbollah leaders deny it.
Imad Mughniyeh, Hezbollah's security chief at the time, is on an FBI wanted list with a $25 million bounty on his head, but for a different attack: the June 1985 hijacking of a TWA airliner at Beirut airport in which a US Navy diver was killed and the passengers were held for 17 days.
American intelligence officials describe Mughniyeh as Hezbollah's operations chief. One official, who spoke on the condition of anonymity, said counterterrorism authorities don't have a fix on his location, but the official acknowledged reports Mughniyeh had been sighted in Lebanon, Iran, and Syria.
US authorities believe he remains active in plotting terrorist attacks, but they have provided little detail on his recent activities.
Hezbollah won't talk about Mughniyeh, and a Lebanese official said that no one has provided any proof that he was involved in the barracks bombing.
In May, a federal judge in Washington blamed Iran for the 1983 barracks bombing and said Tehran would have to pay damages to survivors and relatives. The judge, ruling in a lawsuit filed by 153 families, said Hezbollah had carried out the attack with the approval and funding of senior Iranian officials.
The Marines came as peacekeepers to a country reeling from an Israeli invasion and occupation and from the massacre at the Palestinian refugee camps of Sabra and Chatilla perpetrated by Israel's Christian Lebanese allies.
But the Americans were drawn into the conflict on the side of the Christian-led government, while Iran, then in full anti-American cry, supported Hezbollah, the Shi'ite guerrilla group fighting the Israelis.
The Americans had already suffered a sharp terrorist blow in April 1983, when a Shi'ite Muslim suicide bomber rammed a van packed with explosives into the seaside US Embassy in Beirut, killing 63 people, including 17 Americans.
The US soldiers who came six months later with a multinational force weren't the only victims of the bombing offensive. On the day the Marines were attacked, a separate and simultaneous blast killed 58 French paratroopers.
The multinational force came to oversee the removal of Israeli, Syrian, and Palestinian forces from Beirut.
But in Lebanon, as in Iraq today, the Americans encountered populations with deep ethnic or religious differences, as well as neighboring governments intent on influencing events.
Many Lebanese distrusted the Americans' motives, believing that the Reagan administration had given Israel an OK to invade Lebanon in June 1982 and later occupy Beirut.
"There was a feeling that the Americans came to wipe out the traces of Israel's crimes in Lebanon, rather than for peaceful purposes," said Talal Salman, publisher of the leftist daily As-Safir.
"That's why the US forces were not treated as friendly forces," Salman said. "They didn't come as Red Cross workers or Protestant preachers. They were regarded as Israel's partners."
Edward S. Walker, a senior State Department official at that time, said the bombing of the Marine barracks had a "very negative impact" because it persuaded the United States to withdraw.
"The long-term implications of that was it appeared to terrorists that . . . all you have to do is hurt the Americans and you will get what you want," said Walker. "That's been a persistent problem for us."