I agree, we do need open borders for all nations, to become a one-world-nation called Earth.
Those around here with access to rational, logical common sense, know that any such undertaking takes planning.
Computers are great at running scenario simulations and we need hudreds of thousands of people ----using the minds--- playing the Make-the-World-Work game.
And this can subcataorized for the many various aspects for regional concerns and specialities. Ex deserts are great for solar power, if not also wind power.
If humanity is going to survive another 1000 years, then playing World-at-War is not going to work anymore. That only leads to Zombie-land-Apocalypse.
Humanity is evolving into brown colored skin world of mixed RNA-DNA. Get over it help to the future { in our minds } and leave the past reality behind { in our butts }.