A few years ago, the Pentagon's secretive Office on Special Operations and Low Intensity Conflict quietly buried one of the most comprehensive reports ever commissioned on the changing patterns of global terrorism.
The "Terror 2000" findings compiled by 41 experts - including former ranking CIA, FBI, State Department and Rand Corp officials as well as an ex-KGB general and Israeli intelligence agent - were deemed too alarmist and far-fetched. "Outrageous", said one CIA official. Even a sanitised version designed to promote public preparedness was axed.
The only catch is that many of its predictions have been realised and include that international terrorism would reach American shores, potentially targeting a major US financial centre, and that home-grown zealots would pose major threats to domestic security.
Within three years of the 1993 report, bombs at the World Trade Centre in New York and the federal building in Oklahoma City became the deadliest acts of international and domestic terrorism carried out in the US.
Terror 2000 also predicted that overseas extremists would use chemical or biological agents in some major subway systems. In 1995, an extremist group released sarin nerve gas in a Tokyo subway, killing 11 and injuring thousands. "There's only been one. But then we haven't yet hit the year 2000," the project director, Mr Marvin J Creton, noted wryly in a weekend interview.
The lesson, looking back, is that of all the forms of warfare that exist at the 20th century's end, terrorism may be the most intractable. The simultaneous bombings of US embassies in Nairobi, Kenya, and Dar es Salaam, Tanzania, last Friday underscored that lesson with deadly force.
Whether motivated by ideological hatred, financial greed or religious passions, terrorists have moved further and faster in devising imaginative targets and tactics than government counter-terrorism officials can keep up with.
Looking forward after the east Africa carnage, Terror 2000 offers a road map. One of its fundamental conclusions, endorsed by a host of independent experts, is that trends in terrorism will continue to mutate in the post-Cold War world.
Even the most conservative prognosis contained in the report is that terrorist acts against the US are likely to increase at an annual rate of at least 15 per cent for several years to come. Since the report was issued, the rate has jumped up and down erratically, with no clear trend.
But the volatile period envisioned in the report is distinguished by what it calls "superterrorism", involving sporadic but sensational attacks, often featuring advanced weaponry.
"Future terrorists will find they need ever more spectacular horrors to overcome this [American] capacity to absorb what previously would have seemed intolerable," the report states. "We must be prepared to defend against dangers that only a few years ago seemed impossible."
Perhaps the most ominous development is that, like everything else, superterrorism is going global.
Consider one hypothesis about Friday's devastating car bombings: the sites hit were in Africa. The real target was an ocean away in the US. Several terror groups deemed capable of such an attack are in the Middle East and south Asia. If the bombs contained Semtex or C-4 - extremely powerful explosives used in several major terrorist acts - the raw materials may have come from a fourth continent, Europe.
In one respect, Friday's embassy bombings run counter to recent trends. Because of heightened security, the number of attacks on US diplomatic and military personnel plummeted from 200 in 1986, to 39 in 1995, and to eight in 1997, according to the State Department.
But in other key regards, the east Africa bombings appear to fit the trend toward attacks against less defensible targets such as tourists, private businesses and their clients, and even children.
They also underscored the fact that Americans increasingly are the intended targets. During most of the 1990s, almost 40 per cent of all international terrorism incidents have been against US citizens and facilities. Extremism is often characterised by fewer, but deadlier, attacks. Bombings are the primary tactic. In 1997, 108 of 123 anti-American attacks involved bombs, according to a State Department report.
In one uncannily accurate prediction, Terror 2000 warned that extremists might try to maximise their impact by moving beyond isolated attacks to multiple, simultaneous targeting, thus demonstrating their reach and taxing governments' ability to respond.
That's exactly what happened in Africa, when the two car bombs exploded within minutes of each other in cities 450 miles apart.