The United States and China will talk next week about China's growing involvement in Latin America.
In the past two years China has invested billions in the region - which Washington has, up to now, regarded as its sphere of interest.
The United States has been losing influence in Latin America
Charles Tang cuts an arresting figure.
He negotiates the uneven Sao Paulo paving stones in his well-cut pin stripe suit, tall, alert, wearing the smile of a man who believes in his vision.
Latin music seeps out from a nearby building, and Tang appears to sway in time with it, a child of the Chinese revolution who walks and thinks like a Brazilian.
He left Mao's China as a baby, went to Hong Kong, then to the US, became a banker and 30 years ago fell in love with Brazil.
He now chairs the Brazil-China Chamber of Commerce, and has a direct line to the Brazilian and Chinese leadership.
He is also behind a series of initiatives which is setting off alarm bells in Washington, where increasingly China is compared to the Cold War Soviet Union.
"The Chinese government has removed 400 million people from poverty," says Tang,
"They participate in economic life and live with dignity."
"So that could be a model for Brazil?" I asked.
"Absolutely", he said. "Because that is the true victory for human rights. That's what human rights are all about."
In Tang's view, the Chinese way of doing things outstrips any formula laid down by Western democracies and the International Monetary Fund.
China's economic growth, for example, is four times that of Brazil.
Chinese money has been ploughed into Brazilian industry
Since an exchange of visits between Brazil's left-leaning President, Lula da Silva and China's President Hu Jintao two years ago, Chinese money has been pouring into Latin America, transport, energy, ports, steel - all under the umbrella of a new strategic partnership.
After meeting Tang, I ended up in the Brazilian heat, shoes clogged with ploughed earth, in a field where sugar cane was being planted.
The cane is made into the bio-friendly fuel ethanol, and Tang wants to broker a deal to sell ethanol to China.
The workers there, heads covered against the sun, faces grained with a life on the land, get paid seasonally by how much they plant or harvest.
"What about the new markets in China?" I asked.
They had heard about them.
"The more work we get, the more money we earn," said one of the older men, his expression impassive.
He took off his hat, wiped his brow and stared at the ground. The others nodded.
"How many of you support Lula?" I asked.
The manager escorting us nervously pushed dead cane with his foot.
Afterwards, my interpreter explained. "They don't understand politics or political systems. Most of them are illiterate.
"You've got to remember Brazil is a Third World country with one of the world's widest social gaps."
The day before, in Sao Paulo, I had been sitting with Francisco Marten, a supermarket worker, whose real interest is politics.
He is a slight man who walks the pot-holed streets of his poor neighbourhood, deep in thought, head down, bag slung over his shoulders.
While we talked, children played barefoot in the road; men drank at a makeshift bar; cheers from a soccer game came over the rooftops.
Francisco was once a supporter of President Lula.
Now, feeling betrayed by him, he has joined a hard left movement, the Socialist Urban Workers Party.
"What about this political mood in Latin America with all these left-wing leaders winning?" I asked.
"More of it will happen," he says. "It's about education. It is a cry from the people to invest in education so they can move on and know about their rights."
Lula is Brazil's first left-wing president in four decades
Francisco clarified two apparently separate strands - from Charles Tang and from the sugar cane workers - that have become that single thread which has made Washington sit up and take notice.
The previous week I had been in the US capital hearing Dan Burton the Republican Congressman who chairs the committee on Latin America.
He was telling me communist Chinese money coupled with the rise of leftist leaders were worrying him.
"Chavez, Castro, Ortega, Morales in Bolivia and their connection with communist China," he said. "I think we need to pay particular attention to that."
As far back as 1823, the United States introduced a policy for Latin America known as the Monroe Doctrine, decreeing that no foreign power could have more influence there than the US itself.
It was last used in earnest during the Cold War.
"Is there a line which you wouldn't let China cross?" I asked Mr Burton.
"There are already military exchanges and hardware being sold, or given, to Latin American countries," he said.
"We're watching that very closely and deciding on what we would do if and when things go too far."
He paused, then went on to underline his point.
"We should always look at Latin America in relation to the Monroe Doctrine.
"It's extremely important that we don't let a potential enemy of the United States become a dominant force in this part of the world."
From Our Own Correspondent was broadcast on Saturday, 1 April, 2005 at 1130 BST on BBC Radio 4. Please check the programme schedules for World Service transmission times.