In the past four years, dozens of German citizens have been recruited to train in al Qaeda-connected camps in Pakistan, according to US and German law enforcement officials. German language jihadi videos on the internet help to attract more trainees.
"Some are German converts, many are Turks, many are Arabs," said Guido Steinberg, a counter-terrorism analyst at the German Institute for International and Security Affairs. "Right now we already have the first Afghans and even Iranians in these circles. It's a very mixed bunch of people -- quite international."
"The American authorities are extremely nervous about what is going on, the Germans are extremely nervous about what's going on," said Steinberg.
"The advantage, of course, is the passport," said Steinberg, "because with the German passport it's a lot easier to travel."
Travelers with German passports do not require a visa to enter the United States.
Steinberg said that many of the German jihadis who train in Pakistan are killed, "but those who come back are a threat. "And they are a threat not only to Germany," added Steinberg, "but also to our allies and especially the U.S. because they are extremely anti-American."