Berlin » Midway through a propaganda video released last month by a group calling itself the German Taliban, a surprise guest made an appearance: a clean-shaven, muscular gunman sporting the alias Abu Ibrahim the American.
The gunman did not speak but wore military fatigues and waved his rifle as subtitles identified him as an American. The video contained a stream of threats against Germany if it did not withdraw its troops from the NATO-led mission in Afghanistan. Although the American's part in the film lasted only a few seconds, it has alarmed German and U.S. intelligence officials, who are still puzzling over his background, his real identity and how he became involved with the terrorist group.
U.S. and European counterterrorism officials say a rising number of Western recruits -- including Americans -- are traveling to Afghanistan and Pakistan to attend paramilitary training camps. The flow of recruits has continued unabated, officials said, in spite of an intensified campaign over the past year by the CIA to eliminate al-Qaida and Taliban commanders in drone missile attacks.
Since January, at least 30 recruits from Germany have traveled to Pakistan for training, according to German security sources. About 10 people -- not necessarily the same individuals -- have returned to Germany this year, fueling concerns that fresh plots are in the works against European targets.
"We think this is sufficient to show how serious the threat is," said a senior German counterterrorism official who spoke on the condition of anonymity.
German security services have been on high alert since last month, when groups affiliated with the Taliban and al-Qaida issued several videos warning that an attack on German targets was imminent if the government did not bring home its forces from Afghanistan.
There are about 3,800 German troops in the country, the third-largest NATO contingent after those of the United States and Britain. German officials say Taliban and al-Qaida leaders are trying to exploit domestic opposition in Germany to the war; surveys show that a majority of German voters favor a withdrawal of their soldiers.
The videos all featured German speakers who urged Muslims to travel to Afghanistan and Pakistan to join their cause.
"They're doing such good business that they are dropping a new video every week or so," said Ronald Sandee, a former Dutch military intelligence officer who serves as research director of the NEFA Foundation, a U.S. group that monitors terrorist networks. "If I were a young Muslim, I'd find them very convincing."
Last week, German officials disclosed that a 10-member cell from Hamburg had left for Pakistan earlier this year. The cell is allegedly led by a German of Syrian descent but also includes ethnic Turks, German converts to Islam and one member with Afghan roots.
Other European countries are also struggling to keep their citizens from going to Pakistan for paramilitary training.
In August, Pakistani officials arrested a group of 12 foreigners headed to North Waziristan, a tribal region near the Afghan border where many of the camps are located. Among those arrested were four Swedes, including Mehdi Ghezali, a former inmate of the U.S. military prison at Guantanamo Bay, Cuba.
Meanwhile, three Belgians and a French citizen are facing trial in their respective home countries after they were arrested upon their return from Pakistani camps last year. The suspects deny they were part of a terrorist conspiracy or plotting attacks in Europe. But one defendant has admitted to French investigators that the group received explosives training while in Waziristan. Three other Belgian and French members of the alleged cell are still believed to be at large in Pakistan or Afghanistan.
European security officials have warned for many years of the threat posed by homegrown radicals who have gone to Afghanistan and Pakistan to wage jihad. Officials in some countries, such as Britain, said they have successfully cracked down on the number of would-be fighters going to South Asia. But others, such as Germany, are seeing a significant increase and struggling to contain it.
In the past, such volunteers were largely self-motivated and had to find their own way to South Asia. Today, however, al-Qaida and its affiliates have developed extensive recruiting networks with agents on the ground in Europe, counterterrorism officials said. The agents provide guidance, money, travel routes and even letters of recommendation so the recruits can join up more easily.
In a recent report, the Dutch General Intelligence and Security Service said there were a "growing number of indications" that more Europeans were attending camps in the border region between Afghanistan and Pakistan.
The Obama administration has said that al-Qaida's command structure and operations wing have become weaker in the past year because many of its leaders have been killed in drone missile attacks. But in its report, the Dutch intelligence agency offered a different assessment, saying that al-Qaida's ability to carry out attacks has generally improved in recent years largely because it has successfully bolstered its alliances with other terrorist groups.
"With the jihadist agenda of those allies becoming more international, at least at the propaganda level, the threat to the West and its interests has intensified," the Dutch report found.
German officials said they have discovered multiple recruitment networks that work for al-Qaida, the Taliban and other groups, such as the Islamic Jihad Union, which has been issuing many of the online threats against the German government. But they said the recruiting networks often operate independently, making it difficult for the security services to detect or disrupt them.
"In Germany, we don't have a uniform structure that recruits people," another senior German counterterrorism official said in an interview. "We have a wide variety of structures."
U.S. residents detained
Another sign of the internationalization of the recruitment networks is the small but growing participation of U.S. residents.
Abu Ibrahim the American, the gunman in last month's German Taliban video, is also being touted as a poster boy for jihadi recruitment on a Turkish-language Web site. The site, Sehadet Zamani, issues propaganda on behalf of the Islamic Jihad Union, an offshoot of an Uzbek terrorist group that now counts Turks, Germans, Arabs and Chechens among its members.
In July, U.S. officials announced that they had apprehended Bryant Neal Vinas, 25, a resident of Long Island, N.Y., who has confessed to traveling to al-Qaida camps in Pakistan and firing rockets at a U.S. military base in Afghanistan.
Vinas, the son of immigrants from Peru and Argentina, is cooperating with U.S. and European authorities. He has testified about his interaction with the six-member cell of recruits from Belgium and France. Vinas has also told the FBI that he spent time in Pakistan with another New York resident, whose identity and whereabouts are unknown.
Last month, the FBI arrested yet another U.S. resident, Najibullah Zazi, and accused him of plotting a bombing in New York. Zazi, 24, an Afghan national who has lived in New York since he was a child, traveled to Pakistan last year.
U.S. intelligence officials have said that he made contact with a senior deputy to al-Qaida leader Osama bin Laden and learned how to make homemade bombs. Zazi said he went to Pakistan to visit his wife but has denied going to a training camp.
Terrorism analysts said the CIA campaign to kill al-Qaida and Taliban leaders had been generally effective, but warned that the strategy had its limitations and that missile attacks alone would not put an end to the training camps.
"The drone attacks seriously weaken these organizations, but you can't rely on that alone," said Guido Steinberg, a researcher at the German Institute for International and Security Affairs. "They obviously have no problem recruiting new members. In the long run, they won't have any problem replacing the leaders who have been killed."
On Saturday, the Pakistani military deployed 30,000 troops into South Waziristan as part of a broad offensive against the Taliban and other militant groups. U.S. and European officials have said they hope the mission will force many of the training camps to shut down.
But analysts said the camps, which offer basic lessons in homemade explosives and countersurveillance as well as weapons training, could easily relocate elsewhere in Pakistan or even back across the border in Afghanistan, where they operated before the U.S. invasion in 2001.
"We're talking about much smaller, much more mobile camps that don't train by the hundreds, but by the handful," said Bruce Hoffman, a terrorism expert at Georgetown University. "They can be repacked and set up again fairly easily and quickly."