It demands a close embrace, a standoff and a slithering walk across the dance floor. I am talking here about South America's sexiest export — the tango.

When we think of the tango, most of us conjure up images of seductive Latin rhythms and sultry moves on sweaty dance floors in South American barrios.

But the music and dance have a long and complicated history, and now, fortunately, thanks to a jolt of international diplomacy, a well-preserved future.

The saying that it takes two to tango turns out to be an accurate description of how quarrels develop, as since the late 1800s there has been a dispute about where the tango was born.

Buenos Aires, the "Paris of the South," has become synonymous with the grace and grittiness of the tango.

But right across the Rio del Plata is Montevideo, the capital of Argentina's tiny, often-ignored neighbour, Uruguay.

Graciela Anton and Manolo dance the tango during a show on the fourth floor of the Borda Hospital, Buenos Aires' largest psychiatric hospital, where the national dance is being used to treat a variety of disorders from phobias to marital breakdowns. (Marcos Brindicci/Reuters)

It is not just the river, or the occasional soccer game, that divides these two capitals. They both claim that the tango was born on their respective soils.

When Buenos Aires' National Tango Academy called the tango the definitive national art form, Uruguay responded with a presidential decree that made the 90-year-old tango song La Cumparsita the country's national hymn.

The right mix

Buenos Aires tends to get all the glory for the tango — in fact we consider the dance as Argentinean as Eva Peron or Che Guevara.

However, there is considerable evidence that the tango actually developed in the lower-class neighbourhoods of the drum-based but otherwise sleepy city of Montevideo.

Consider the evidence: Both cities have a rich mix of ethnicities and cultures that led to this form of music and dance, which was too provocative for the upper class to embrace.

Each had a healthy population of young male labourers, hanging out in the urban slums and brothels where the tango is said to have found its legs.

And if that sociological rivalry wasn't enough to get these two cities fired up, both claim Carlos Gardel as their own.

Father of the tango

Even if you don't know who Carlos Gardel is, chances are you've heard his music and that he has influenced one of your favourite musicians.

Gardel wrote and performed some of the most romantic and painful tango music of the early 20th century.

His crooning and swooning style took him to Paris and New York for regular performances and he made the world fall in love with his rhythms and with the dance that began in the brothels of Argentina. Or Uruguay.

It's not certain where he was born or even what year but one thing is for certain — he was the "King of the Tango."

In fact, when the charming, fedora-clad singer died in a plane crash in 1935, a woman in Havana actually committed suicide and at least two others, in New York and Puerto Rico, tried to poison themselves in despair.

A last tango in Paris

None of these women had ever met Gardel. It was just the sheer power of his music that moved them to these lengths.

Gardel's fans could put Elvis's to shame. He was so beloved that even Colombia and France claim him as their own.

But the real contenders in this tango-ed web were Buenos Aires and Montevideo.

The result was a feud that has been going on for over a hundred years.

But then, earlier this year, something harmonious happened.

The two South American cities sidestepped their argument and two-stepped together to Paris to persuade UNESCO (the UN Educational, Scientific and Cultural Organization) to give the tango protected cultural status in both countries.

I can only imagine that their campaign in Paris, another tango-loving city, must have been something like the dance itself:

A intricate pas de deux between partners framing each other and providing support for the other to perform fancy footwork while simultaneously in competition and squaring off.

Ain't diplomacy grand?

Protection from?

However they performed their presentation, the two cities and their campaign paid off. In September, UNESCO granted the tango protected cultural status for generations to come.

It is now right up there with Chinese calligraphy, Kabuki theatre and Indian Vedic chanting.

But protection from what exactly? Frankly, I'm still not sure.

The tango seems more a part of popular culture now than ever.

Glorious tango dance scenes have been immortalized in movies like Moulin Rouge, Scent of a Woman and Chicago to name just a few.

Or turn on your TV. With the popularity of reality shows such as Dancing With The Stars and So You Think You Can Dance there has been a boom in the number of people signing up for formal dance lessons.

It is a phenomenon that is sweeping much of Asia as well. In fact, a Japanese couple won the international tango competition this year.

But maybe that kind of internationalized, Hollywood-stylized tango isn't what Buenos Aires and Montevideo are trying to protect.

It just may be that despite their decades-long dispute over the tango the two are focused on preserving something that is distinctly South American. Something that was created in a new-world environment in an unexpected fusion of cultures, classes, status and, yes, sex.

That would certainly be a special moment of history worth casting an arm around.

I'm hoping to have a better sense of the magic South American tango and why, for generations, these two cities have been tango-ing back and forth for its love.

Later this month I'll be visiting both Montevideo and Buenos Aires, to see what else divides and binds these two cities across the "River of Silver." But for the time being and hopefully for the rest of history — Viva el tango!