If they're born in the country and lived there their whole life, they're local by any non-racist definition.

Integration is a two-way street. It's a 50/50 responsibility shared between host governments and migrants. From what I see, the Arabs/Muslims in Belgium (btw I'm from the same region so spare me your lectures about tolerance and openness for now) are not doing enough to integrate with the wider community but the Belgian authorities and political elites are not doing enough either to integrate these people and combat marginalization and discrimination that they may experience.

Also, Belgium political system is also not helping given its fractured nature thus limiting its options to effectively tackle those challenges and if we take into account the weak economic reality of Brussels add to that its ineffective fight of organized crime (Funding terrorist attacks and armaments) creating a perfect storm for this type of events to flourish whether in Belgium or spilling into other parts of Europe like what happened in Paris last November.

Sure, there are loads of problems due to ghettoisation or whatever.

That has nothing to do with 'recent migration policies'.