Immigration wasn't stopped. It is allowed and limited under specific circumstance. Not a difficult concept. We don't stop people from driving cars what we have are laws that must be complied with to drive a car. Drivers license, insurance, age requirement etc... If you don't follow the law you will be penalized for it. The connection is the population explosion you want. You also stated a nations strength is in numbers. China has every nation beat in that regard yet they are still held at bay. How is that exactly if not for technological wonders. That's the connection to China and you finally admitted you want free markets to decide. No laws no borders. At least you understood that. Free market is your idea. What does the free market do with excess labor it cannot support? Not at all you made it clear people have limited choices based on wealth, education, skills etc... and cannot afford to leave and go elsewhere.