U.S. officials and experts say growing Islamic extremism in Europe poses a significant threat to the United States. The issue was examined at a recent Senate Foreign Relations committee hearing.

The State Department's coordinator for counter-terrorism, Henry Crumpton, told the Senate Foreign Relations Committee, Washington has good reason to worry about Islamic extremism in Europe, following the Sept. 11, 2001 terrorist attacks on the United States.

"The terrorist cell that conducted the 9/11 attacks did much of its planning from a base in Europe," said Henry Crumpton. "Five years later, and despite many counter-terrorism successes, violent Islamic extremism in Europe continues to pose a threat to the national security of the United States and our allies."

Recent incidents in Europe linked to Muslim extremists include bombings in Madrid and London.

In his testimony, Assistant Secretary of State Daniel Fried said the majority of Western Europe's more than 15 million Muslims are moderate. But he said he believes Muslims in Europe find Islamic extremism increasingly attractive because they are alienated from European societies in which they live.

"Many marginalized Muslims, who cross the threshold into extremism, seem to be driven by a sense of spiritual alienation," said Daniel Fried. "They're less concerned than were their parents with economic survival in Europe. Many of Europe's second and third generation Muslims seem to long for spiritual fulfillment."

Disaffected Muslims, especially young people, showed their numbers in protests last year in France. Fried adds that he believes many of Europe's Muslims who feel marginalized do not find their needs met in local, mainstream institutions.

"Foreign financiers and religious activists, often from abroad, fill this spiritual vacuum, by building local mosques, and supplying them with extremist imams," he said. "Disconnected from often tolerant traditions of their families' original homelands, these Muslims are susceptible to foreign propaganda, and sermons that preach narrow and hateful interpretations of Islam."

Although these officials devoted most of their testimony to discussing integration problems that exist in Europe, Senator George Allen indicated one reason why this is also an important issue for the United States.

"While it may not be so obvious, though, there are implications for the United States," said Senator Allen. "The United States and Europe enjoy an open travel arrangement, making it simple for anyone carrying a European country's passport to come to the United States on a day's notice. Thus, how Europe handles this issue is important for our own homeland security."

Robin Niblett, of the Center for Strategic and International Studies, a public policy organization, said terrorists do not have to come to the United States to do damage to U.S. interests.

"Muslims, extremists, do not need to travel to the United States to be able to undertake attacks," said Robin Niblett. "They can take on American targets in Europe. They can take American targets in Iraq. In essence, they are getting their fill of attacking America, and proving they can, without having to come over here."

Meanwhile, Niblett says, he is worried that the level of frustration and alienation in many of the Muslim communities in Europe is still strong and, therefore, dangerous.

"The risk of another terrorist attack is real," he noted. "If another attack happens, the backlash will be severe. Even without another attack, levels of alienation are going to continue, and removing them will be a long process."

Niblett says he believes this process of dealing with Islamic extremism in Europe is just beginning. And, he adds, Western governments are not, in his words, "totally in control of the agenda to try to resolve it."