Violent protests a year ago during a warm-up tournament for the World Cup caught everyone by surprise, including police and troops who struggled daily to contain them.
Tear gas wafted into the Maracana stadium during the Confederations Cup final between Brazil and Spain, and police and soldiers clashed with protesters just a few hundred meters (yards) from the Rio venue.
Social problems and rising prices that set off the protests a year ago still linger. Brazil will deploy hundreds of thousands of police, soldiers and security guards around the 12 venues, and up and down its long border with 10 other South American countries.
Here's a look at the general security and crime picture with the World Cup just a month away.
TROOPS, POLICE, AIR AND SEA
Brazil will deploy about 150,000 troops and police in the 12 cities — and an added 20,000 security guards. In addition, about 10,000 specially trained elite riot troops will be available. Last week Brazil also assigned 30,000 army, navy and air force troops to secure its 17,000-kilometers (10,600-mile) border against drug trafficking and smuggling.
Brazil has received training from several countries in dealing with crowd control. Brazilian officials have said the United States has contributed, as have France, Britain, Japan, Canada and Germany.
"We have cases of violence in our cities, violence with social origins, common crime, robberies," Sports Minister Aldo Rebelo has said. "We are trying to contain this. We know our country may be harmed when this violence is seen by the world, as would any country where violence exists."
RIO BEEFS UP
In Rio, about 2,000 extra police have been put on the streets a month before the kickoff. Authorities were not planning to beef up until just before the June 12 kickoff.
"We've really perceived an increase in crimes. We've seen a gradual increase since the second half of last year," Rio state security head Jose Beltrame said.
In March, muggings in the area around the Maracana doubled when compared to the same month the previous year, according to an analysis of police statistics from the O Globo newspaper.
The Maracana will play host to seven World Cup matches including the final on July 13.
Additionally, police and drug gangs in recent months have engaged in several sharp exchanges of gunfire in several so-called "pacified" shantytowns around the city. Some of the fiercest fights have taken place in a slum located just one block from tourist-favorite Copacabana beach.
ROBBERY AND ASSAULT BIGGEST THREAT
The Brazilian government this week quietly cut its estimates of foreign World Cup visitors in half, from 600,000 to 300,000. Another 3 million locals are expected for the matches, but fewer outsiders may reduce the crime problem.
The biggest threats to most fans will be robbery and assault. Security around the stadiums is sure to be robust, but police may be stretched thin in other areas of the cities. Tourists could be inviting targets in hotel and entertainment areas.
Much of the crime takes place around the cities' favelas or shantytowns, home to about 20 percent of Rio de Janeiro's population.
Criminals can be brazen. Earlier this year a local TV crew in Rio was interviewing a woman on camera about crime in the area. As she was speaking, a mugger came up from behind, ripped off her necklace and ran off.
The Belgian government has suggested that its citizens at the World Cup should keep a little cash to hand over if they are assaulted. Thieves get angry if they come away empty handed. It also suggested caution using bank cards and credit cards.
PEACEFUL PROTESTS PERMITTED
Brazilian authorities say they will allow peaceful protests, but these will only be permitted in areas at least a mile (2 kilometers) from the stadiums.
Brazilians angry about rising price and the billions spent on football stadiums are likely to protest, and may get mixed in with members of the Black Bloc, an anarchist group that has already announced its intention to protest. Their protests have often caused damaged storefronts, looting and torched vehicles. Labor groups and people displaced by stadium construction are also likely to air grievances.
Nationwide protests are expected Thursday, coming the day after Rio ends a two-day bus strike.
Jerome Valcke, the top FIFA official in charge of the World Cup, said recently it was "naive" to think there would be calm as long as the Brazil team stays in the competition.
"It goes beyond that," he said. "Reasons for being in the streets in 2013 have not changed. There are social problems in Brazil. It will take time."
RIGHT TO THE TOP
President Dilma Rousseff, who is up for re-election in October. She's also concerned about security.
"We will guarantee the security of fans, tourists, teams and the heads-of-state that will visit us," she has said. "I am certain we will host the cup of cups."
Valcke has repeated the same pledge.
"I'm sure that the safety of the World Cup will be at the highest level for all people involved," he said. "The highest level of security you can imagine."
Even without World Cup protests, Brazil's cities can be dangerous. It has more cities on the list of the world's 50 most dangerous metropolises than any other, with 15 entries, according to the Mexico-based Citizen Council for Public Safety and Criminal Justice.
Stephen Wade on Twitter: http://twitter.com/StephenWadeAP