THE juices are flowing even if the traffic isn't.

The build-up is nearly over even if the construction work isn't. Excitement is running even while the metro system stands still. You can say Brazil has waited six-and-a-half years to stage a World Cup since its bid was accepted by FIFA in 2007, or you might feel that the amount of time served actually stretches to 64 years. Not since 1950 has the greatest football nation of them all hosted a World Cup but at last the years, months, weeks and days are down to the last few remaining hours. Tonight, the drum roll ends and Brazil opens the show.

This is a World Cup about dreams and reality. What you've seen packaged and tied with a ribbon during the run-in has been the dream vision of Brazil, the country of Samba, of play on the Copacabana, of Pele, Gerson, Tostao and Rivelino, of expression, joy, dancing girls and goals. The Brazil of five World Cup wins.

This is the ideal that has appealed to at least a couple of generations of football fans since the 1970 finals propelled Brazil into the public consciousness, establishing it as numero uno, the most intoxicating country football has ever seen. A child might be puzzled about why 15 tournaments have come and gone since the finals were last held in Brazil, but the last few months have provided some answers. Brazil has struggled to show itself capable of coping with the monstrosity the World Cup has become. The television news showed a chain of workers hurriedly passing building materials along a line with the desperate urgency seen by passengers trying to get cargo off a sinking ship. That's how down to the wire it's been. The sound of the Samba? More like the sound of hammering, drilling and heavy machinery on the move.

The reality so far has been a World Cup of civil unrest and protest about government spending on hosting a World Cup while much of the city suffers grinding poverty and will see the football only on televisions in the favela slums. In Sao Paulo, where Brazil open against Croatia tonight, the metro has been closed by a strike, choking the city's road system even further.

If there was a momentary pause in this last-minute dash to finish the host stadiums it came when news reached workers on Monday that Neymar had been injured in a training session. The news was unthinkable. Neymar cannot be injured (and thankfully he wasn't really, merely a knock on the ankle). When Neymar was born in 1992, Nirvana's Nevermind was at the top of the album charts. That feels like yesterday, yet this slip of a boy carries the hopes and expectations of a 200,000,000 population on slender shoulders. If the Selecao are to win it can only be on the back of one talisman's propulsion, as it was when Diego Maradona's Argentina won in 1986. Brazil have the masterful Phil Scolari in charge and Thiago Silva, Oscar and David Luiz in their side but they do not look capable of winning a World

Cup unless Neymar hauls them

over the line.

Even then, can Neymar match Argentina? The world-class forward count stands at Brazil 1, Argentina 4 (Gonzalo Higuain, Sergio Aguero, Angel Di Maria and of course Lionel Messi). Messi is under pressure of his own, with plenty reckoning that this is the tournament he must dominate to "prove" himself the greatest of all time, but he isn't carrying the same weight of responsibility as Neymar because he has such a wonderful supporting cast. If the tournament runs to seedings and form, Brazil would have to beat the Netherlands, England and Germany to reach the final while Argentina would face perhaps Switzerland, Portugal

and Spain.

Spain are intriguing. No team

has won four consecutive major championships, but then no team had won three until they followed Euro 2008 and World Cup 2010 with another triumph at Euro 2012.

They did not concede a single goal in the 10 knockout games they won in those tournaments although some of them were narrow wins and even the best stumble eventually.

Sometimes the greats suddenly hit the wall, even failing to emerge from their opening group, and being in with the Netherlands and Chile in Group B gives the champions some high hurdles to clear from the start. It is 52 years since a country last successfully defended a World Cup.

Spain are additionally fascinating because they have become the strikerless team which found a striker. What sort of difference will Diego Costa make, other than creating a backdrop of boos at their games having chosen to play for his naturalised country rather than Brazil, the nation of his birth?

Spain are by far the most persuasive European contenders

as neither of Germany, Italy or Portugal has enough world-class talent. England will probably run into Spain in the last 16 if they win their group and Brazil at the same stage if they are runners-up. They are too ordinary to burrow far into the competition but Daniel Sturridge and Raheem Sterling might illuminate their challenge for

a while.

Costa is 25, Messi and Aguero 26, Wayne Rooney 28, Cristiano Ronaldo 29 and Andrea Pirlo 35. Neymar is 22. Will it be a World Cup which best suits the fitness of youth or the self-discipline and experience of age?

Brazil is huge - the USA squad will cover over 10,000 miles in

20 hours of flying time between their base and their three group games - and the vast geography covers significant differences in heat and humidity. The truly hellish venue in that respect is the Arena Amazonia in Manaus, a city built in the Amazon jungle. FIFA did not have

to wait until the 2022 finals in Qatar to run into trouble over playing conditions: the Brazilian footballers' union has protested about the conditions across a tournament in which 24 matches will kick-off at 1pm Brazilian time, including six in the searing heat of the northern venues. The only concession was FIFA's decision to introduce three-minute breaks after 30 minutes of each half if the forecast is to be over 32 degrees at kick-off. They will show advertisements during those breaks, of course, what with FIFA needing the money. One fact has been ubiquitous going into this tournament: no European team has won a World Cup held in South America. It is a point that does not carry a great deal of significance. The 1930 and 1950 finals in Uruguay and Brazil were so long ago that they have no relevance. Brazil were so strong in Chile in 1962 they would surely have won the tournament wherever it was staged. In the 1978 final the Dutch broke through at 1-1 in stoppage time and hit the post; a couple of inches and they would have been world champions. The host venue has not been the major factor in these World Cups and football is now so global, and so homogenised, that Spain, Germany, Italy or Portugal will not feel that they are playing with any sort of insurmountable handicap.

The bookies have Brazil and Argentina as favourites, in that order, and if they both win their groups they cannot meet before the final.

It is 64 years since Europe did not have a team in the final. Brazil versus Argentina would be an assault on the senses: Neymar versus Messi, the two great South American rivals meeting for the

first time in a final, going head-to-head in the Maracana.

The repugnant Sepp Blatter does not deserve a climax as thrilling as that, but Brazil, and football, does.