What role did the Eastern Roman Empire play in the fall of the Western Roman Empire? Did the Eastern Empire actually contribute to the fall of the West? Was the Eastern Roman Empire able to help the Western Roman Empire around the time of their collapse (they were definitely wealthier and more populated, but did they have enough manpower and resources to significantly make a difference)?"
The following two sources are somewhat unreliable, but summarize the problem.
The Eastern Emperors did, with their vast sums of gold, pay off Hunnic and Germanic tribes that were harassing the Danube frontier from Pannonia to the Black Sea to leave them alone and go off somewhere else. This somewhere else was the Western Empire. Allempires.com
As for the relationship between the 2, it was more often one of mistrust and interference rather than close alliance and friendship. Yahoo Answers