If same thing happened to Pakistan (not happening but lets imagine) then these Afghanis wouldn't have allowed us anywhere near Afghanistan. Do you know how Iran treat them? Despite being so called "Iranic" brothers. Why is Pakistan worried about refugees but not Iran? Because in Iran they are treated like animals in zoo, not allowed to go anywhere.
Those who have been born in Pakistan and consider it their "home" should become Pakistani.
This sign is common in Iran
No Afghans allowed in Iranian park | The Lost Flaneur
And Afghanis themselves are ready to sign surrender document and have been fighting alongside Nato in last decade. Do you blame Pakistan for that also? If they hate Nato then tell them to not sign surrender document...