Why the "ROMAN Catholic Church"? Why not just, the "Catholic Church"?

I'm studying the Book of Revelation these days and am enjoying it greatly.  I found some great introductory stuff for how to read the Bible from Peter Kreeft's, You can Understand the Bible: A Practical and Illuminating Guide to Each Book of the Bible, and N.T. Wright's Simply Christian.  

I found this quotation from Michael Barber in his book, Coming Soon: Unlocking the Book of Revelation.

"Ever wonder why it's so important that we are not only 'Catholic,' but 'Roman Catholic'?  The early Christians knew why.  Saints like Peter and Paul went to Rome hoping that, by the shedding of their blood, the fourth beast would convert, so that the kingdom of God would be made manifest through it.  The term 'Roman Catholic,' then, reflects not some kind of implicit political allaince between the Church and Italy, or any other earthly power, but the fulfillment of God's plan, which He announced through Daniel."

So, it was not by random chance that Sts. Peter or Paul went to Rome.  St. Paul's insistence to be heard by the Emperor in Acts moves us along these lines.  Also, the fact that Acts ends with St. Paul in Rome, preaching the Gospel of the kingdom.  

This also moves us further into the Book of Revelation: is "Babylon the great," of which St. John speaks, Rome or Jerusalem?  Interesting.