The Taliban resurgence in Afghanistan has allowed al-Qaida to regroup in the Afghan-Pakistan border region, terrorism experts report.

In fact, foreign jihadi militants are joining the Taliban fight against U.S. and allied forces in Afghanistan. Fighters from Turkey, Central Asia, Chechnya and the Middle East have joined the fray in Afghanistan, which has become what the Associated Press termed the "most active front" in the war on terror.

Al Qaida has been recruiting on jihadist Web sites, inviting the "Lions of Islam" to fight in Afghanistan, according to Brian Glyn Williams, a professor of Islamic history at the University of Massachusetts who has tracked the movement of jihadists for the U.S. military.

The return of Arab fighters to the border region has concerned local Afghans, Mr. Williams wrote. Also arriving in Afghanistan are Turks. "The story of Turkish involvement in transnational jihadism is one of the best-kept (secrets) of the war on terror," he said.

Dozens of Turkish Islamic militants have trained in al-Qaida camps in Afghanistan and participated in attacks there, according to a Turkish terrorism expert, Emin Demirel. The foreigners are more likely to use suicide bombing tactics, experts say.

A senior Taliban leader, Qari Mohammed Yusuf, confirmed the growing presence of al-Qaida, which has financed the Taliban in Pakistan and Afghanistan. The U.S. military has been watching the arrival of foreign fighters into Afghanistan and Pakistan.

Obviously, the dynamics are changing in the region. The Pentagon's decision to mount a "surge" of U.S. troops in Afghanistan "sooner rather than later" is further evidence.