Last month, France revealed that at least five French citizens had died fighting as Islamic terrorists in Iraq. One of them died as a suicide bomber. This month, Spanish police rounded up 16 men suspected of being active with Islamic terrorist groups, particularly Ansar al Islam. This outfit has been dominated by Kurds, and has received support from Iran in the past (largely to provide another irritant for Saddam Hussein.) Since Hussein fell in 2003, its unclear how much support Ansar is getting from Iran. But Ansar is a major player in Europe, where it raises money and recruits people to undertake terror operations outside Europe. Ansar in particular, and Kurdish activists in general, have followed this policy so as to preserve their base of operations in Europe, where about a million Kurds live. While only a small percentage of those support Islamic radicalism, it's enough to make Ansar one of the largest Islamic terrorist groups in Europe. Moreover, Ansar works closely with Islamic groups that do carry out terrorist attacks in Europe.
Until recently, European counter-terrorism forces merely watched the Kurds, and Ansar. The arrangement, that kept Kurds from being violent in Europe, was respected by European police, until it was noted that the Kurds were tight with a lot of quite violent (in Europe) terrorists (particularly the bunch that bombed Madrid in March, 2005). When French and German police dug into their Kurd files, and pressed those they had in custody, they found Ansar to be a major player in the terrorism universe.
Ansar al Islam was founded in late 2001, with the help of al Qaeda. From the beginning, it was largely Kurdish, and determined to unite all Kurds in an Islamic state. Violence and terrorism committed in Iraq by Ansar has made the organization unpopular there. But in Europe, Kurds dont suffer from those attacks, and see Ansar as heroic freedom fighters.