- Bringing more eyes and ears in the form of social workers and community policemen in problematic neighborhoods.
- Provide better education/work opportunities for immigrants.
- Better cooperation between municipalities and Muslim organisations/mosques.
- Deradicalization programs.
Of course, implementing such policies takes time and it's much more popular to present the 'easy solutions' (more surveillance, closing borders, etc.).
France has been doing pretty much the opposite, investing money in surveillance and special forces instead. Belgium has kind of ignored problems.
That's part of the problem right there that people segregate into enclaves and have little contact with each other's communities.
Meanwhile, people are dying. That is exactly how some people see it, and exactly how I see it. I'm not emotional, I'm logical, and I expect government to protect us from evil individuals/groups. Arguably, it's not there to foster some sort of "long-term" sustainable co-existence between different cultures.
First, you establish security and root out potential problem groups. And once that's happened, and you have almost non-existent danger to the local populace, then you can start worrying about integration and grey-goals such as "peaceful coexistence" and "de-radicalization". And I don't say that as a means to single-out immigrants, or foreign groups. This reasoning should apply just as much to dangerous elements that are within, and part of society currently.
Just before Christmas last year:
French police have foiled an attack targeting police and army personnel in the central city of Orléans, Interior Minister Bernard Cazeneuve said on Tuesday. Two men have been arrested.
...
Cazeneuve said 10 attacks had been prevented this year in France, which suffered its worst atrocity for decades last month when Islamist militants killed 130 people in Paris.
http://www.france24.com/en/20151222-france-terror-plot-foile...
Exhibit A: The Mossad is generally considered one of the best intelligence services world-wide.
Exhibit B: There are still frequent terrorist attacks in Israel.