Al-Qaida remains a "potent" international terrorist network with more than 18,000 trained members at large in up to 90 countries, and could take a generation to dismantle, a leading international affairs thinktank warned yesterday.

The warning came in the annual strategic survey of the International Institute for Strategic Studies whose author, Jonathan Stevenson, said the Riyadh bombings "bore the hallmarks" of an al-Qaida operation.

The bombings "may be the first indication that the regime change in Iraq in the short term is going to cause a terrorist backlash and be an inspiration for terrorists", he added.

In the 1980s Washington's secret services had assisted Saddam Hussein in his war against Iran. Then, in 1990, the US fought him in the Gulf. In both Afghanistan and the Gulf, the Pentagon had incurred debts to Islamist groups and their Middle Eastern sponsors. By 1993 these groups, many supported by Iran and Saudi Arabia, were anxious to help Bosnian Muslims fighting in the former Yugoslavia and called in their debts with the Americans. Bill Clinton and the Pentagon were keen to be seen as creditworthy and repaid in the form of an Iran-Contra style operation - in flagrant violation of the UN security council arms embargo against all combatants in the former Yugoslavia.

The Bosnian Muslim army was covertly supplied with arms by the US during the 1990s

• Sheena McDonald "US involvement in Bosnia stretched the Western Alliance to breaking point"
• Lt General Sir Michael Rose "We knew the US were secretly bugging our offices"
• Captain Oivind Moldestadt

  According to Norwegian Air Force Captain Oivind, on 10 February 1995, United Sates forces alone controlled Bosnian air space for the entire night. This was NATO's task, which had an AWACS plane called "Magic" which routinely flew combat air control missions with two fighters. According to the classified NATO flight record for 10 Feb 1995, the normal NATO planes were secretly ordered to stand down and replaced with a smaller U.S. Navy E-2 Hawkeye AWACS and American FA-18 fighters. "This indicates to me that, during this incident, this evening, not NATO, but the Americans were controlling the entire Bosnian air space, on their own."

According to the Pentagon's Defense Science Board, a strong correlation exists between U.S. involvement in international situations and an increase in terrorist attacks against the United States. President Clinton has also acknowledged that link. The board, however, has provided no empirical data to support its conclusion. This paper fills that gap by citing many examples of terrorist attacks on the United States in retaliation for U.S. intervention overseas. The numerous incidents cataloged suggest that the United States could reduce the chances of such devastating--and potentially catastrophic--terrorist attacks by adopting a policy of military restraint overseas.