Mr Giuliani cannot alone take the credit for the humbling of the Cosa Nostra in New York, but he can take a share. His record stretches back to 1983, when, as district attorney for the city, he destroyed with a series of convictions the famed "Pizza Connection", centred on the grip that the Mafia had on heroin imports into the United States.
Prosecutors today are upholding that early Giuliani legacy. The case against John Gotti Jr may critically weaken the Mafia from top to bottom. One item in evidence: a list found in a Gotti home of all the "made men" of all five Mafia families. Investigators have called it their Holy Grail.
These days, Mr Giuliani's main weapon is regulation. By turning over control of the fish market to the city, he has watched as prices of fish have dropped by 5 per cent in three years. The destruction of the Mafia cartel that used to control all rubbish collection from commercial buildings in Manhattan has had a similarly spectacular effect. An estimated $400m (pounds 250m) has been cut from the waste-collection bills of office towers, restaurants, hospitals and hotels.
Despite their recent run of startling successes, Italy's Mafia-fighters are not happy: "Anyone who mentions the Mafia these days is considered a nuisance," said Palermo's chief prosecutor, Gian Carlo Caselli, last week.
With Pierluigi Vigna, head of the national anti-Mafia prosecutor's office, Mr Caselli is the most exposed of Italy's crime-busters. His frustration at what he perceives as lukewarm support from Rome is tangible: "We're accused of acting only to protect our own power bases," he said. "There's a real campaign against us."
Perhaps equally discouraging is the fact that the people of Italy's crime- plagued south are showing signs of giving up the uneven struggle against the Mob.