Fernando Alonso was world champion in 2005 and 2006

Can it really work this time?

The last time Fernando Alonso joined McLaren, he left the team one season into a three-year contract after falling out spectacularly with the team's figurehead, Ron Dennis.

Seven years on, the two men find themselves cast together all over again, in the hope that this time the story ends a little more happily.

Up and down the Formula 1 paddock, the thought of the single-minded two-time world champion and McLaren's overbearing chairman working together again continues to be viewed with incredulity.

How, many people ask, can McLaren have voluntarily re-signed a man who effectively cost them nearly £50m and got them thrown out of the 2007 constructors' world championship?

It's an important question in the context of the 33-year-old rejoining McLaren - if, to some extent, a misleading representation of what happened.

So, before we turn our attention to 2015, and the prospects for driver, team and their new engine partnership with Honda, we have to take a closer look at what happened a little over seven years ago during that tumultuous summer.

Don't look back in anger

Alonso won four races with McLaren in 2007 but finished behind team-mate Lewis Hamilton in the drivers' championship

Alonso joined McLaren in 2007 straight after winning two consecutive titles with Renault. They were symbolic of the passing of the flame from one generation to the next. Michael Schumacher, beaten in a straight fight in 2006, had retired, and Alonso was established as the new standard in F1.

His season with McLaren coincided with their involvement in the 'spy-gate' scandal, in which their chief designer was found in possession of 780 pages of confidential Ferrari technical information.

At an initial hearing by governing body the FIA, McLaren were found guilty of breaking the rules, but escaped punishment on the grounds there was no evidence the information had benefited the team.

That seemed to be that until a few weeks later when, in the course of a bitter row with Dennis over the weekend of the Hungarian Grand Prix, Alonso threatened to reveal to the FIA potentially incriminating email conversations with McLaren test driver Pedro De La Rosa on the subject of the Ferrari information.

Alonso joined Ferrari in 2010, but 2014 was the team's first winless season since 1993

A little while later, Alonso's adviser came back and apologised, explaining the Spaniard had been upset and wanted to take back the threat.

But rather than wait for Alonso to calm down and talk it over again, Dennis had panicked and phoned FIA president Max Mosley to tell him of the existence of the emails, while assuring him there was "no information, nothing to come out".

It was a miscalculation, albeit an understandable one in the context of the febrile, paranoid atmosphere at the time and Dennis's antagonistic personal relationship with Mosley.

And despite Dennis's reassurances, the case was reopened and McLaren were hit by the aforementioned punishment.

As it turned out, Dennis's phone call made no difference. Mosley already knew about the emails and was planning to re-open the case.

Fernando Alonso 'very different' from 2007 as he returns to McLaren

The point, though, is that Dennis's actions were a reflection of how bad his relationship with Alonso had become, in the context of the knowledge that Alonso's manager was Flavio Briatore, then the team principal of Renault.

Briatore was a close friend of F1 boss Bernie Ecclestone and - like Mosley and Ecclestone - no fan of Dennis on a personal level.

Whether or not Alonso's threat was real did not really matter. Once he made it, the result was inevitable. If Alonso knew, Dennis figured, so did Briatore - and, given the relationships involved, it was asking too much for that information not to make it to Mosley one way or another.

And Dennis was right - Mosley says now that he knew about the emails because Alonso had told Briatore about them, and Briatore had blabbed.

'The very best driver of his generation'

Alonso has won 32 grands prix in a F1 career which began in 2001

Why, you might wonder, would McLaren want Alonso back, after all that?

The first and most important reason is obvious - because they believe he is about the best driver out there.

The second is that McLaren need to make a statement of intent at the start of their relationship with Honda, and signing Alonso is a big one.

The third is that Honda badly wanted him - the Japanese company have long been huge fans of the Spaniard.

In tempting him away from Ferrari, McLaren-Honda have secured a magnificent driver, as his former colleague Rob Smedley can attest.

Before joining Williams this year as head of performance, Smedley spent 10 years at Ferrari, gaining three years of first-hand experience of Schumacher and spending his final four years as Felipe Massa's race engineer, with Alonso on the other side of the garage.

"Fernando is the very best driver of his generation," Smedley says. "I would go so far as to say if not the best ever. He is that good. He brings that much performance to the team. I am a massive fan of his.

"To have Fernando as your team-mate, as most people have found out - Kimi Raikkonen has certainly found out this year - is not easy. You are talking about very good drivers who sit beside him on the other side of the garage. I don't think there is anyone in this paddock who could live with him."

Time the great healer

Alonso and Ron Dennis fell out at the 2007 Hungarian Grand Prix

On the day of the row in Hungary, McLaren's then managing director Martin Whitmarsh tried to persuade Dennis to sack Alonso immediately - before that weekend's race.

Yet, some years later, Whitmarsh admitted he did not at that point have all the relevant information and when he did, he was more understanding - if not forgiving - of Alonso's actions.

The issue at the heart of the problems within McLaren all that year was Alonso's demand for the team to focus their title challenge on him, rather than split their efforts by giving team-mate Lewis Hamilton equal status.

That was true to McLaren's long-stated ethos. But Whitmarsh later discovered that when Dennis signed Alonso he had indeed promised him priority status, only to go back on his word.

As for Dennis, when he was asked about Alonso's behaviour following the FIA's punishment of McLaren, he said, almost admiringly: "Competitive animals know no limits."

It was Whitmarsh, who became team principal at McLaren in 2009, who started the process that has led to Alonso rejoining the team.

Whitmarsh approached Alonso as long ago as the summer of 2013 to make it clear he wanted him back. And the process of wooing him continued despite Dennis's ousting of Whitmarsh late last year.

A winning pitch

Dennis became team principal of McLaren in 1981

Whitmarsh's effective replacement, McLaren's racing director Eric Boullier, has been instrumental in convincing Alonso that he has a better chance of winning the elusive third title he craves at McLaren than at Ferrari, even though their competitive positions in 2014 suggest otherwise.

Part of Boullier's sales pitch has centred on Honda. The Japanese company and McLaren are intent on reviving the glory days of their original relationship a quarter of a century ago, when with Ayrton Senna and Alain Prost they won four drivers' titles in a row from 1988-91.

Alonso, who has had a year of watching Ferrari's new turbo hybrid V6 engine pummelled into the ground by that of Mercedes, has been informed of Honda's progress and apparently been convinced that the Japanese engines have a better chance of taking on Mercedes than those from Maranello.

Fernando Alonso has 'mixed feelings' on leaving Ferrari

Equally, although McLaren's car has clearly been well behind the best in the past two years - and well off Ferrari's, too, for that matter - the team have been making changes.

Specifically, these include the signing of aerodynamicist Peter Prodromou from Red Bull, where he was the right-hand man of design guru Adrian Newey on the cars that romped to four consecutive world titles from 2010-13. In three of those years a frustrated Alonso was second.

There have been all sorts of rumours over the past few weeks about how exactly Alonso came to be leaving Ferrari two years before the end of his contract.

But the man himself says that his intentions have never wavered. "In the summer, I took the decision," he says. "I followed that direction and only time will tell whether it was a good one or a bad one."

Sources close to Alonso and Ferrari insist that is true.

They say that he simply wanted to leave Ferrari, having lost faith that they would ever get into a position to challenge for the title within the timeframe of the years he has left at his peak - which, at 33, is probably only a handful more.

Mercedes, where there is no seat open for 2015, were his first option; McLaren his second.

A man obsessed with success

Alonso divides opinion in the F1 paddock

Walk up and down the paddock and it is not hard to find people who will say Alonso is a disruptive influence and hard to handle, while, equally, there are also those who have worked closely with him who will barely say a bad word about him, and insist that he is "only as difficult as you allow him to be".

But whatever Alonso's actions, they are based on his overwhelming will to win. He is desperate to win a third title, and with it the status he rightly feels he deserves in the F1 pantheon.

He gives everything in his quest to achieve that and he expects his team to provide him with the equipment to do so.

If there is going to be a problem between Alonso and McLaren in the next little while, its root will likely be there.

Formula 1 2014 season in numbers

Alonso and Dennis have apparently buried the hatchet. But they will never be bosom buddies. After all, Dennis, a difficult and complex character, has fallen out with every good driver who has ever raced for him - Prost, Senna, Niki Lauda, Mika Hakkinen, Juan Pablo Montoya, Kimi Raikkonen, David Coulthard, Lewis Hamilton and Jenson Button.

But Dennis and Alonso will likely rub along well enough as long as things are going well, especially with Boullier acting as a buffer.

The issue will be if they are uncompetitive.

Alonso has gone to McLaren to win, and win big. Perhaps not next year, but sooner rather than later. If they don't deliver, or if they don't at least look like they are going to, the fall-out is unlikely to be pretty.