LONDON - A British think-tank says "neo-Taliban'' groups operating in Pakistan's tribal areas may soon become a global menace.

Nigel Inkster, who directs a risk analysis unit at the London-based International Institute for Strategic Studies, says such groups "have the potential to turn a local threat into a transnational threat.''

Inkster also says there is "some evidence'' that such groups were involved in  the assassination of Benazir Bhutto and that they have dispatched terrorists to the United Kingdom and Spain.

He said international terrorism remains a "growth industry'' and that the groups in Pakistan had earned the "dubious honour'' of making the most strides in the last year.

In its annual report on the world's military forces, the institute found that the situation in Iraq had improved because of the surge in U.S. troop levels ordered by President George W. Bush.

But director-general John Chipman warned these advances would be swiftly undone if the U.S. draws down its troop strength too quickly.

He said U.S. troop levels had to stay high to prevent an increase in Shiite military activity, provide security for any provincial elections and keep violence in Kurdistan from increasing.

Chipman said the prospect of U.S. military action against Iran had diminished in the last year after U.S. intelligence reports played down Iran's nuclear threat, but warned that Iran still appeared to be developing its nuclear weapons potential.

"Iran shows no sign of abiding by United Nations Security Council demands to stop its current enrichment activity,'' he said.