I think the problem is that the Roman empire was on the brink of collapse so many times, it would have been weird for someone to think one particular time was special. The troubles of the Third Century, for instance, looked a lot worse at the time than anything after that, but the empire recovered just fine.
The first (of several) sack of Rome in 410 AD was probably a huge red flag. But by then, Rome was not even the capital of the Western Empire any longer. The sack was mostly a symbolic loss, Rome having been able to defend herself for a thousand years.
In hindsight, permanently moving the capital from Rome to Constantinople was what might have turned the page for the empire. It was a complex series of changes, placing a new religion without strong ties to Rome on top, moving the political center of the empire to the East, and freeing the emperors for a while from the pressure of the senate and the people.
I note that the Eastern provinces were economically outperforming the Western ones by large margins even before Barbarian incursions. That the East would run the empire was probably inevitable at some point.
I think the problem is that the Roman empire was on the brink of collapse so many times, it would have been weird for someone to think one particular time was special. The troubles of the Third Century, for instance, looked a lot worse at the time than anything after that, but the empire recovered just fine.
The first (of several) sack of Rome in 410 AD was probably a huge red flag. But by then, Rome was not even the capital of the Western Empire any longer. The sack was mostly a symbolic loss, Rome having been able to defend herself for a thousand years.
In hindsight, permanently moving the capital from Rome to Constantinople was what might have turned the page for the empire. It was a complex series of changes, placing a new religion without strong ties to Rome on top, moving the political center of the empire to the East, and freeing the emperors for a while from the pressure of the senate and the people.
I note that the Eastern provinces were economically outperforming the Western ones by large margins even before Barbarian incursions. That the East would run the empire was probably inevitable at some point.
I think of it more that the collapse of Rome took over a millennium. Rome was so large that the state could collapse and reform several times.