As someone who has lived in UK for sometime and have grown up childern ( son and daughter) I am very much aware of this problem.
Unfortunately, every action has 'pros' and 'cons'. When I chose to shift to UK, it implied that I would be faced with this dilemna when my children grew up. I have seen childern of friends marrying Europeans. It is a statiscal fact that in a place where there are ten times more white boys and girls than brown ones ( religion makes the pool even smaller) a young boy or a girl; specially those who grew up in the UK; are more likely to find a non brown person that they like.
I have known cases where people from a less educated background ( mostly from Mirpur in Azad Kashmir) have taken their nubile daughters back home and forcibly married them to their cousins; only for the women to run way and hide in the British Embassy and eventually return to UK.
I send my kids to Pakistan ever so often with the hope that they would find someone they like without much success. One of the reasons I dislike Taliban and Mullahs is that their actions are making my children anti religious. I have no reasonable answer when an idiot blows himself up in the Bari Imam mosque and kills score of innocents. Is this what Islam is all about?? the guy did it because he thought he will go to heaven, my daughter asked me, she was visiting Pakistan at that time. On the other hand in some families, specailly less affluent ones, boys are inclined towards jehadi culture and girls have started wearing Hijab. I am not against hijab but think that the cultural divide is causing extreme reactions as there is a crisis of identity among the young.
I am dreading the day when my son or daughter comes home and tells me that they want to marry this or that person but if it does happen, there wouldn't be a lot I could do. The problem is a real one and acute.