Five years after the London bombings, in which 52 people died, homegrown terror remains a concern across Europe. More dialogue and a coordinated strategy is how EU countries hope to tackle the problem.
Homegrown terrorism is a relatively new term - and a new phenomenon. But Europe has learned through experience that it is a danger from within that cannot be ignored.
Five years ago, on July 7, 2005, four bomb attacks on the London transport system left 56 dead and countless wounded. One year earlier, the Madrid attacks claimed the lives of 191 people.
This article was prepared by the Islam in Europe blog - islamineurope.blogspot.com
In Germany, the so-called Sauerland terror cell had devised attacks on airports that were only prevented because the group's plans were uncovered shortly before they intended to carry them out.
Homegrown terrorism is different from attacks like those in the United States on September 11, 2001. The perpetrators come from the very countries they attack, where they grew up and went to school. Most come from secular immigrant families and are brought up without religious zeal.
They seem well integrated into society - until they come into contact with Islamist extremists. Some of these homegrown terrorists do not even have a Muslim background and only convert to Islam when they become adults.
Some argue that the crucial lesson learned in the wake of the London and Madrid attacks was that efforts to foster closer cooperation with Muslims in European countries need to be stepped up.
"It's essential that we work with those parts of society where trends toward radicalization can occur," says Ole Schroeder, a parliamentary state secretary in the German Interior Ministry. "For instance we have to directly work with mosques or with groups close to radical Islamists."
The best protection, Schroeder says, is to ensure that Muslim communities in European countries are not susceptible to extremist tendencies. The German government has tried to take a step in this direction by founding a forum on Islam aimed at creating a dialogue with Germany's Muslim population on shared societal values.
After the London attacks, European Union member states decided to join forces on the issue; Spain with its large Moroccan population is, for example, to devise a model on how such training can best be done.
"The Spaniards have the responsibility for expertise on the training of imams and passing it along to the other countries," said Magnus Ranstorp of the Swedish Defense College in Stockholm.
In Britain, the authorities are also working together with mosques and Muslim communities to prevent the radicalization of young men. The British government has initiated a program with more than 260 publicly funded projects aimed at reaching out to the Muslim population. Mentoring schemes are one aspect.
Some argue that if a person is not susceptible to extremist ideologies, he or she won't turn to terrorism. Among those who subscribe to this line of thought is Judith Sunderland of Human Rights Watch.
Her group says that banning minarets or the burqa only leads to further radicalization. Terror suspects, they say, must never be treated with disrespect to the rule of law - as has been the case in several western counties.
"Measures that are taken to counter terrorism that ultimately violate human rights, in the long run, feed the grievances and the sense of injustice that can fuel radicalization."