The picture says it all: A smiling Dilma Rousseff is looking down on her predecessor, Luis Inacio Lula da Silva, as Brazil's former president lies in a hospital bed waiting for chemotherapy. He still may be the most popular politician in the country, but she's clearly in charge.

Since Rousseff became president in January, there has been speculation that she took the job just to hold it safe for her former boss to return in the next election.

But Dilma, as she's known here (her presidential website is Dilma.com), is no fill-in.

When scandals rocked the government a few months into her mandate, she abruptly fired her chief of staff, a close ally of Lula's. Since then, she's slain many a powerful politician, almost all of them associated with the previous administration.

The issue was corruption. One after another, the Brazilian media published details of kickback schemes and corruption in the departments of transport, agriculture, tourism and, most recently, sports.

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Rousseff visits her former boss, Lula, in his hospital bed in October. In the middle, Brazil's Finance Minister Guido Mantega. ((Associated Press))

The embarrassment became an opportunity to clean house, fire senior bureaucrats and, in the name of austerity, reduce the amount of money available for political pork-barrelling.

In the midst of everything, she also dumped the powerful defence minister for disparaging remarks he made about her and several cabinet ministers. (He was reportedly angry that she overruled him on a big fighter jet contract.)

Her no-nonsense style has raised hackles in the old boys network that has run Brazilian politics for decades. And it has apparently provoked some in her governing coalition to call her naïve for trying to confront something as systemic as corruption in Brazil.

They say that she may have started something she can't stop because everyone who's accused of something will start pointing fingers at someone else.

Voters don't seem to mind, however, especially, it seems, among the growing middle class, who are organizing regular and ever larger protests against corruption.

But it is possible her big test is still to come as she takes on FIFA, the governing body of soccer's World Cup, which is already trying to force Brazil, the next host, to bow to its will.

Dilma vs. FIFA

When Lula put Rousseff, a trained economist, in his cabinet back in 2002, she was considered a highly efficient manager who didn't brook fools.  

Some have called her Brazil's Iron Lady, after former British prime minister Margaret Thatcher. When she was minister of mines and energy, I was told she called a leading businessman in one of Brazil's most powerful industries into her office and that he left the meeting in tears.

The World Cup, however, is on a different scale altogether.

Brazil has won soccer's elite trophy a record five times, but as the tournament's next host in 2014 it's not winning any accolades.

Former star players such as Romario, now a congressman, and Pele, the soccer legend who is the president's honorary ambassador for the World Cup, say Brazil is nowhere near ready to host the event. Promised airports, stadiums and other facilities are way behind schedule.

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Rousseff and soccer legend Pele, in less confrontational times, promise that everything will be ready for the World Cup in 2014.

The delays are alarming FIFA, whose president, Sepp Blatter, wrote Brazil recently demanding it do better or risk losing the prestigious event.

But FIFA's threat isn't sitting well here. Politicians right across the spectrum are already angry with the sports body for demanding that Brazil change many of its laws — mainly to protect FIFA's lucrative deals covering sponsorships, trademarks and broadcasting rights.

FIFA even demanded Brazil alter its constitution, which guarantees half-price tickets for seniors.

Rousseff refused to back down on that one and FIFA appears to have given in.

But it is still pushing Brazil to make another controversial change to its laws —  lifting the nationwide ban on liquor sales in stadiums. That would deliver FIFA's chosen beer sponsor huge profits during the month-long tournament.

'So who are you?'

A local magazine has billed this battle over the beautiful game as a "duel" between Dilma and Blatter, who is expected here later this month to push for all the legal changes to be signed off on by the end of November.  

To bolster the government's side, a special Senate committee invited Andrew Jennings, the British investigative journalist who has been digging up dirt on FIFA for the past 10 years, to share any evidence of corruption in the organization.

He's advising Brazil not to give in. "FIFA imposes outrageous conditions on any country hosting the World Cup," Jennings says. "And for once, a sovereign nation, Brazil and its president, Dilma are saying, 'Wait a minute, you're asking us to change our laws? Why should Brazil agree to these terms? Who are you?'"

Like Brazil, FIFA is also battling serious corruption allegations these days, mostly thanks to Jennings's investigative work.

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On the president's side, an increasing number of street protests are campaigning against Brazil's seemingly institutionalized corruption. ((Connie Watson))

Caught up in some of these allegations is Ricardo Teixeira, the longtime boss of Brazil's soccer federation and its top man in FIFA.

Teixeira is currently under investigation in Brazil and has been the subject of other political investigations over the years, even as he's managed to hold on to power. He says he's innocent of all charges but the president has noticeably cooled her dealings with Teixeira, who heads Brazil's World Cup organizing committee.

For his part, Jennings says Dilma shouldn't even have her picture taken with FIFA's leaders when they show up this month.

"We know Brazil is very keen to tell the world it's arrived," he says. "If, as a country, they take FIFA on and say 'You're not going to screw us,' this will give courage to others around the world. And I think this would be part of a wonderful celebration of the World Cup coming here in 2014."

As for Dilma, her crackdown on corruption may yet set off a mutiny within her own government. But duking it out with FIFA — at a time when its reputation is under attack — probably carries more reward than risk for Brazil's first female president.