As an admiring Englishman of the United States of America I sincerely hope my proud Cousins do not fall like the Roman Empire! Historically all states come and go have their heyday decline or perish. I the case of the U.S. however it would be highly unwise to predict anything of this kind.America has the advantages of a generally extremely flexible economic system and can adapt rapidly the change unlike many of the older European States is more open than possibly anywhere to innovation and novelty. I therefore reserve my final assessment but hope that the country remains free proud and strong!

Yes. The fall has already begun. Luckily for us that such things take so long to happen completely. Not so lucky for those who have kids.

This question has been of great interest to me. A big part of the fall was the assimilation of other cultures (#1 on your list) which became impossible to manage. The Roman government tried to get Roman citizens to have more children to keep up with the outsiders but failed. Often governments trie to control fertility rates but usually don't, look at Japan today.Too much diversity can spoil the broth and few countries seem to get that including ours. I have a degree in European History and spent time in Rome studying it's history so this goes a little beyond opinion.

Of course, like many country, the USA doesn't seem to learn from history

Every civilization before them has fallen and when you get too high, there's only one direction left...down

What i really wonder is what is going to happen with the banking system... it won't last forever

Every civilization so far throughout history has had a rise and a fall. That being said, the inter-related and intertwined nature of the modern world is nothing like anything that the world has seen before, so the US is quite possibly heading for some sort of internal breakdown, but it may not be a civilizational collapse, perhaps just a single country economic collapse.

Just before the fall of the Roman Empire there was decadence, the similarities to today are quite striking. Gladiators were the sport celebrities of the day, there were even celebrity chefs. Today I see decadence everywhere, it won't be just the US that can fall, but all the western capitalist countries are vulnerable. Just look at the banking crisis, which we have not recovered from yet.

Actually what did Rome in was lead poisoning - especially among elites that could afford lead water pipes in their domiciles. Once the elites went crazy everything fell apart. In modern times it might be "smart phone" poisoning and restriction of communication to verbal/text only mode which makes people extremely vulnerable to manipulation and propaganda.