Michael Bloomberg is a man on a mission. This, of course, isn't the first "noble cause" he's latched on to but the "evil" of tobacco is something he feels particularly strongly about.
In co-operation with the Bill and Melinda Gates Foundation, Mr Bloomberg has just launched a multi-million dollar fund to help smaller countries fight legal battles with tobacco companies, among them the small South American country of Uruguay.
Uruguay has considerably fewer smokers than Michael Bloomberg's usual backyard of New York but this country of just three million people has become an unlikely battleground between anti-smoking campaigners and big tobacco. Its government is embroiled in a long running and expensive legal battle with the cigarette industry over its anti-smoking laws.
And the former Democrat, come Republican, come Independent once touted as a potential presidential nominee has stepped into fray.
"We are in this to help countries that can't afford to defend themselves against an industry which will try to kill a billion people this century," Bloomberg tells me, pulling no punches in his New York headquarters.
"If that isn't a noble cause I don't know what is. You can talk about saving society but you have to translate that into action."
Smoking in the developing world
Although tobacco consumption is falling in the west, the opposite is true in the developing world. That's why Gates and Bloomberg have set up this fund.
In Uruguay itself the proof of the pudding is in the eating, so to speak. A country, which used to have the highest smoking rates in Latin America, is witnessing tobacco consumption decline rapidly. Silvina Echarte, from the Health Ministry's dedicated anti-tobacco strategy group, says this is all down to new, aggressive laws.
"We have numbers, we have scientific evidence saying that these kind of policies and the enforcement of these kind of policies have been effective," says Echarte.
Those laws include directives which mandate that 80% of a packet must be covered in health warnings and there's a complete ban on tobacco advertising and promotion.
Most egregiously, say the tobacco manufacturers, a company cannot sell more than a single variation of the same brand: Marlboro Red and Marlboro Light, for example.
That legislation goes too far say the cigarette companies and that's why the test case between the tobacco giant, Phillip Morris International (PMI) and the government is seen as so important; the right of an individual country to pursue its own aggressive health policies against the commercial freedoms of the cigarette companies.
Tobacco is, of course, a perfectly legal product and is sold around the world. Where it can advertise, Phillip Morris' marketing and promotional ads are clever and well produced; urging smokers "not to be a maybe", to try something different.
'We do not target kids'
Health campaigners say the industry deliberately targets young people. That allegation is emphatically denied by PMI.
Cigarette companies don't often give interviews to the media, perhaps feeling - with some justification - that they're always portrayed as the villain in the piece. But on this occasion, PMI did agree to speak to me at their international headquarters in Lausanne, Switzerland.
Senior Vice President and Chief Legal Counsel Marc Firestone categorically denied those accusations of trying to "pull in" young, would-be smokers.
"We do not target kids, that is not our audience," Firestone tells me. "We do seek to maintain brand loyalty among existing adult smokers and there are many who prefer our brands and those who don't currently prefer we would like them to switch to our brands."
Firestone rejects the suggestion that Uruguay is being deliberately "targeted" by the cigarette industry as part of a broader strategy to scare off smaller countries perhaps contemplating similar legislation. His accusation is that Uruguay's laws breach existing trade agreements.
"We had to withdraw seven of our 12 brands and obviously that disrupts our ability to compete in the marketplace with lawful products. So that's why I say the regulation itself is highly unusual," says the man from PMI.
'It's going to be a big fight'
Michael Bloomberg may be a champion of the capitalist system and made his own fortune in the free market but the tobacco companies' arguments don't wash with him.
"There's nothing else I will do that will save as many people," Bloomberg tells me. "It's going to be a big fight. You've got to do something about these companies. You can't just sell something that if used as advertised will kill people."
Michael Bloomberg has made himself unpopular before with his campaigns against the gun lobby and global warming but you get the distinct impression that it's his money and he'll spend it as he wants on the issues he cares about.