No way Jose. The concept that Western Civilization will decline and will end as its enfeebled countries become too weak to resist invasion and subsequently become overrun by other cultures it's not realistic in our case.
The fact is that the American culture dominates other cultures and we can see that in the US. Despite the many cultures that exist here there is only one that predominates. It is clear that in one way or another it is the American culture, which dominates, or attempts to dominate the rest of the word. The result will be an Americanized world far away from extinction.