Yesterday's embassy bombings abruptly ended an 18-month period of relative quiet which may have lulled US security services into complacency.
The number of American casualties from international terrorism last year fell to one of the lowest levels in 25 years, a decline attributed by the US state department to its law enforcement agencies in tracking those responsible.
Nine states are on the American government's list of "terrorist sponsors", although Iran remains the "most active" backer of Islamic extremist attacks despite the more conciliatory posture of Iranian president Mohammed Khatami who came to power a year ago.
The last big incident was in June 1996 when a US military housing complex in Saudi Arabia was blown up, killing 19 American airmen and wounding 500.
An exiled Saudi dissident, Osama bin Laden, described as one of the world's most dangerous terrorists, is wanted both for the Khobar Towers barracks bombing and a carbombing in the Saudi capital Riyadh the previous year which killed five Americans.
Mr bin Laden, believed to be based in Afghanistan, is suspected of funding the bombing of the World Trade Center in New York in 1996. The massive explosion killed six and injured 1,000. Four people were convicted of the WTC bombing, including the Muslim cleric Umar Abd a-Rahman, an Egyptian national, and Ramzi Ahmed Yousef who had been extradited from Pakistan.
The last time an American embassy was targeted so directly was in September 1984 when a suicide bomber presumed to be from Islamic Jihad blew up the US embassy in East Beirut killing 40 and wounding dozens. Another suspected Islamic terrorist, Mir Aimal Kansi, is facing trial for the murders of two CIA officials in January 1993 at CIA headquarters in Langley, Virginia
In March 1995 two US consulate employees were killed in Karachi when their shuttle bus was attacked and in February 1996 a Palestinian gunman killed one tourist and wounded 12 others at the Empire State building in New York before shooting himself.
A note he carried said the attack was punishment for "the enemies of Palestine".Reuse content