World On Brink Of Ruin NEW YORK - Alan Greenspan, that Matador of the Money Supply, the esteemed Impresario of Interest Rates, has suffered precious few slings or arrows over his many years as chairman of the Federal Reserve. Even the White House has had to offer its critiques off the record for fear of roiling the markets or upsetting the chairman's Elvis-in-Vegas-like following. So when the chief economist of one of the world's most prestigious banks calls Greenspan a bum, that's a big deal. And yesterday it happened. Stephen Roach, the chief economist for Morgan Stanley & Co. (nyse:...