As far as I know Rome never fought with Sparta. By that time Sparta was not to be considered a military power to be reckoned with.
Romans were able to defeat the different Greek powers by simply using one against the other. In most of the battles there were more Greeks fighting against other Greeks than actual Romans. Overall the idea was that first there was a war with the Kingdom of Macedonia and then the Romans turned on Southern Greece with most prominent event the destruction of Corinth.
Roman yoke on Greece was relatively light. Already before Rome had interfered militarily in Greece the two people were increasingly in touch and most prominent Romans received a Greek education. This later led to a kind of "kinship" between the two cultures, as they're known the "GrecoRoman civilization".
Romans after the devastating wars with Carthage and especially after being trained in war by the hard lessons in defeats at the hands of Hannibal barca, were now the most devastating war machine the world has known. They could draw reserves from a vast manpower base and their military techniques were well advanced. It was only a matter of time after the destruction of Carthage to take it up with the rest of the world. Simply "if you have a war machine in your hands, at some point in time you will inevidably use it". Perhaps we can also today learn some lessons from history.
Edited by Yiannis - 08-Jun-2007 at 07:27