Don’t need to double them
They need to burn down the current ones if they still want a country and culture to survive
Why can’t European leaders offer to pay natural born citizens of their countries $15,000 per year if they will but birth a child, and stay home and raise it. Double it to $20,000 per year if they have 3. Pay them that until the children are all college age. Pay them $10,000 per year after they are all college aged until the lady dies if she has 4 or more. It has to be cheaper or close to the same as providing social services for the Muslims that are going to kill their nation anyway.