"Failing to integrate them" could be because they struggled to find jobs, due to unions acting as a cartel and shutting competitors out of the labor market.
If Norway accepted fewer immigrants, that means that fewer jobs for immigrants are needed. If you accept a lot of immigrants, you'd like to have employment opportunities for _all_ of them. Unionization could cause this problem by lowering demand for unskilled workers, who are no longer profitable to hire due to union bargaining.
If jobs for immigrants were plentiful, maybe government support wouldn't be necessary.
If Norway accepted fewer immigrants, that means that fewer jobs for immigrants are needed. If you accept a lot of immigrants, you'd like to have employment opportunities for _all_ of them. Unionization could cause this problem by lowering demand for unskilled workers, who are no longer profitable to hire due to union bargaining.
If jobs for immigrants were plentiful, maybe government support wouldn't be necessary.