What if the Roman Empire never collapsed?
I'm sure this should be in Philosophy, seeing how it relates to time and how things can be different in theory if things were changed. This question has been bugging me for some time now.
Now, What if the Roman Empire never collapsed? What if, instead of succumbing to the barbarian invasions, previous leaders made better decisions that ended in the empire holding their ground, defeating the Hunnic and Gothic forces, and remaining the dominant power in the Mediterranean? Take the Battle of Teutoburg Forest for example. Here's a link.
http://www.unrv.com/early-empire/teutoburg-forest.php
Quintilius Varus was an inexperienced general, in fact he was a senator, which was one factor which lead to the loss of three Roman legions. Another factor was the Germanic warlord, Arminius, who executed the attack. But what if neither of these two people existed? What if Augustus Caesar managed to invade Germania, and occupy it? Indeed, the Battle of Teutoburg Forest caused the loss of three legions, which resulted in Caesar abandoning his expansion into Germania, and instead protecting the borders of the Northern Roman Empire, along the Rhine and Danube rivers. Because Germania wasn't taken, barbarian forces had built up over hundreds of years, creating tribes such as the Franks, the Anglo-Saxons, the Goths, Visigoths, Ostrogoths and the worst, the Huns. These forces combined, ultimately destroyed Roman power in the West.
Change the situation. If Germania, had been occupied, the 27th, 28th and 29th legions still intact, Roman power would eventually move further and further into the east, until all of Europe was under Roman control. Therefore, the tribes of the Franks, the Anglo-Saxons, the Goths, Visigoths, and the Ostrogoths would never have risen, well at least become so powerful. The Huns, coming from the east would likely have been crushed by the Romans, as there would be no support from other tribes to make the invasion more powerful. This would mean that the Roman Empire never would have split, being so powerful and united. So then, Rome becomes the dominant force, Latin is the dominant language, Islam would never have risen due to Roman occupation in Arabia, the Crusades would have never happened. As the Dark Ages threw Europe into technological strife for nearly five hundred years in reality, theoretically, the world we have today would have existed during the middle of the Renaissance, and today's society would be very advanced, considering the Roman's domination of Europe.
Is it possible, however, that this could have been different? Could the now Europe-dominant Romans still have been destroyed in some way? (China maybe?) Is there anything else that may have happened due to the non-existance of the Battle of Teutoburg Forest? Any historians out there on DV, or just the general public, discuss.