People tend to view things through the lens of their own life-time. So for someone who looked at the USA prior to 9/11 to look at it today and to conclude that a lot of damage has been done would be accurate.

What it looks like a hundred years from now is something nobody can make a reasonable stab at. Chances are that by then this has healed and gotten better, chances are that it will get much worse.

"This too shall pass" applies forever, and countries have been born and have disintegrated long before they managed to achieve their goals.