AldavisAlbundyAllah!
All Star
Societies that have constant flow of genetics and new ideas survive, countries that have stagnant growth and low genetic inflow die.
As to why Rome lasted 1,000 years and Sparta last 2 centuries.
Immigration is a positive not a negative. See Japan in 50 years
Greater talent pool. Particularly in the fields of higher science.
Also, more generally speaking, one of the innate benefits of diversity is an inflow of fresh ideas, beliefs, perspectives, etc...
The slogan is MAGA, right?
Have you ever heard of the internet