Take my word for it. These Britain based Pakistanis seem to live in another world altogether. They won't be the ones suffering when the lawless areas come into Pakistan and those people become Pakistani citizens.
It would not end well for Pakistan's social stability or lawfullness. And the ones living in Pakistan would be bearing the brunt of it. Think of the period when the Afghans and Pashtuns from NWFP swamped Karachi.