Now more than ever, a small minority of young Europeans are turning their backs on western values and instead choosing a life of radicalisation and extremism. It may be just a handful of people converting to this disturbing way of life.
However, the challenge of stopping terrorist organisations such as Isis recruiting and radicalising European citizens is one that Europe, and the western world, cannot ignore.
Firstly, there must be a concerted effort by both governments and communities. By pulling together, we stand a far greater chance of overcoming this ruthless and violent ideology.
European governments need to step up checks at our borders, to prevent vulnerable individuals from leaving and being further radicalised.
While this is more easily achieved in the UK, the Schengen agreement makes it difficult in many other parts of Europe. The recent attempted terror attack on the high-speed Thalys service was fortunately prevented, but this exemplifies the difficulty facing security services across a borderless Europe.
An EU-wide policy of restricting or stopping suspects' access to the internet would severely restrain their communication with terrorist organisations.
Perhaps most important is the role that communities can play in countering extremism. One UK organisation that is leading this approach is Muslim Engagement and Development (Mend). Mend's work on counter-radicalisation focuses on activity and advocacy.
These take their cue from successive UK select committee reports highlighting the impact of disenfranchisement and exclusion on people susceptible to extremist ideas and causes.
A UK home affairs select committee report several years ago pointed out the problems with the current counter-radicalisation strategy. It focused on a negative discourse instead of pursuing a positive discourse on engagement, inclusion and political literacy.
Their work is dedicated to just this - engagement, inclusion and media and political literacy. This challenges the media discourse portraying Muslims as the 'other' and addresses misguided policies, like the current 'Prevent' programme, which has proven counterproductive to its aims.
It ensures that counter-radicalisation policy is evidence-based and is used in a way that mitigates unintended consequences, such as discriminating against Muslims.
Importantly, it works with the vast majority of British Muslims, which is the most effective tool against extremists. Through engagement, inclusion and political and media literacy, it is challenging the extremists' narrative that it is impossible to be faithful Muslims in Britain, and Europe.
The fact that the vast majority of Muslims reject extremism and display loyalty to the British state is clear evidence that the extremists are not winning the argument.
By harnessing Muslim voices in the public and political spheres, Mend is promoting a positive discourse on British Muslims as a means of counter radicalisation.
While there is no simple solution to this crisis, there are many avenues to be explored to find ways to prevent the problem. We must all work together to ensure that extremism is stamped out once and for all.