Fernando Alonso and Jenson Button could both leave McLaren at the end of the season

There's no doubt that McLaren find themselves in a very sticky situation with regard to both their drivers at the moment.

McLaren chairman Ron Dennis gave one of his better to-the-point interviews to the BBC after the Japanese Grand Prix and tried to give the impression everything was all right with drivers Fernando Alonso and Jenson Button.

But the reality of the situation is that, even though McLaren have contracts with both for next year, it is far from certain at this stage whether either will stay.

This has all come about because of Honda's lack of performance, the lack of progress in terms of engine development during the season and the lack of belief from either the drivers or the team that Honda has a clear sense of how to improve things for next season.

Let's take Alonso first

He has two more years remaining on his McLaren-Honda contract, but the team radio messages he gave during the Japanese Grand Prix betrayed his frustration - as did him saying afterwards that he did not know whether he would still be in F1 next year.

I know he has since put out some statements saying effectively: "Nothing to see here, everything's OK."

But I'm as sure as I can be that we can take it as read that this is little more than a PR exercise.

The fact is, Fernando could walk away from McLaren at any time if he was not happy, and the only thing he would forfeit is money, not face or honour.

Alonso's frustration boils over

We have not seen a driver just walk away from a situation for many years - Nigel Mansell retired after two races for McLaren in 1995 and James Hunt and Niki Lauda both quit partway through the 1979 season.

Having said that, I'd be surprised if he left McLaren at the end of this year.

McLaren's competitiveness is not going to change between now and the last race - Alonso admitted that himself at the weekend.

So I expect he will ride it through to the beginning of next year.

As we saw with Ferrari's big step forward on the engine front last winter, a lot can change from one season to the next.

Alonso will get an indication of where Honda are in pre-season testing next year and then validation at the first race of the season in Australia.

If it looks like Honda has taken a significant step forward, he will probably go marching on. If it doesn't, I could well see someone like that going: "Ladies and gentlemen, Fernando Alonso has left the building."

What about Button?

Button staying with McLaren - Dennis

As for Jenson, it is a question of whether Dennis's statement after the race that he had told Button on Thursday that McLaren would not be taking their option to release him caught the wave of his commitment.

The frustration that Button betrayed after the Singapore race the week before Japan, and which convinced the British newspaper reporters that he was on the point of retirement, was partly to do with a difficult race, partly the lack of the performance of the car and partly Dennis's inaction on confirming whether he wanted Button to stay next year.

We filmed a feature with Jenson on Thursday and, while he was in a good enough mood, he was not giving away hints about his future.

And when I asked him about it, he said: "Whatever happens, I am in a happy place."

All of which did make it seem it was not quite as slam-dunk as Dennis's statement that the contract would be taken up as is would suggest.

My personal experience of Dennis is that once he has looked you in the eye and shaken your hand, he honours it. But anything less than that and you might find him later falling back on claiming that he had not quite said what you thought he had.

The reassuring thing was to hear him admit that this was the worst time McLaren had had in F1. That sort of honesty is refreshing, but also suggests that he does realise they have hit rock bottom and the only way forward is to confront the issues head on.

Red Bull's engine drama

Dietrich Mateschitz (right) has lost interest in Formula 1, says former world champion Niki Lauda

We should not be in any doubt that Red Bull are serious when they say they will quit F1 if they cannot get a competitive engine for next season.

Whether you agree with it or not, they have been entirely consistent in their frustration with the situation with Renault, in whom they have lost confidence. They will split at the end of the season.

It's not unlike the situation with Alonso and Button. If people feel there is a genuine will on behalf of their partners to find solutions, they don't bad-mouth them. They try to defuse the difficulties. When they don't, that's when the problems start.

There are a number of people at the top of F1 now who say what they see and whether you agree with it or not, they tell you what they think. Red Bull owner Dietrich Mateschitz and adviser Helmut Marko are among them, along with Mercedes' Toto Wolff and Niki Lauda.

Red Bull have made it very clear their relationship with Renault has broken down. They have tried to get Mercedes engines but their attempts were rejected.

What we have now is a situation where a billionaire who owns two teams is not prepared to accept second best. It is an understandable position.

It's one thing to have a Renault V8 under the previous engine formula that was 5% down on the best and make that up with the excellence of the car.

It's another to be in the hybrid era and to be offered second-grade Ferrari engines when you are a Grade One team. I wouldn't accept that if I owned Red Bull either.

In that situation, why should Mateschitz carry on pumping hundreds of millions a year into F1 and the show it provides to TV viewers while accepting he cannot win, until such time as he finds a better solution down the road?

It all adds up to a pivotal point in F1 history. If the heads of agreement signed by Renault to buy Lotus does not turn into a full sale, and if Red Bull do not get parity on engine power with the works Ferrari team, there could be six fewer cars on the grid next year.

The problems of not communicating

It is an interesting period in F1 right now, with everything going on behind the scenes.

It seems to me, the thing that binds it all together is communications - or lack thereof.

If Red Bull and Renault had good communications, the relationship would not have broken down. If McLaren and Honda had good communications, they would not have even started this season with such a bad engine; Honda would have waited another year.

Button and McLaren, too - lack of communication.

It all goes to show - it's good to talk. Clearly these guys aren't.

Rosberg's just not doing it

Nico Rosberg is second in the drivers' championship behind Mercedes team-mate Lewis Hamilton

Following Lewis Hamilton's victory in the Japanese Grand Prix, the world championship is all over bar reliability issues.

Hamilton has been a winning machine this year. Nico Rosberg is a talented racing driver and without Hamilton in the team he would be world champion.

But, for me, F1 is not about just being a champion, it is about putting yourself against the best and finding out whether you are capable of beating them - and then becoming champion.

Rosberg drove a very solid race to come back from fourth place to finish second in Japan, but it was all about the start.

Rosberg was slow off the line from pole, but he still had an opportunity to fend Hamilton off into Turn Two and he was not able to make it stick.

He went off the track because Hamilton drove him off the track by not giving him a line - which is perfectly legitimate.

If Rosberg had gone off the track because he braked too late in an attempt to keep Hamilton behind, that would have showed aggression and intent.

It is like when Hamilton ran a little wide at Silverstone back in July to try to take the lead at the restart. He didn't need to do that - but he was prepared to take the risk because he wanted to get the pass done.

Hamilton and Rosberg's wheel-to-wheel start

That is what we have not seen from Nico. He made mistakes and ran off the track last year when leading in Italy, which handed the win to Hamilton, and on the first lap in Russia, when he was poised to take the lead.

Hamilton makes mistakes, too - but not when he's at the front. He makes them trying to get past people.

He is prepared to put things on the line and deal with the consequences and, good as Rosberg's pass was on Williams's Valtteri Bottas in Japan, we have not seen Nico do that against Lewis.

He can drive poles, take wins, and make passes. But he needs to be able to do it against everyone, and from lights out to chequered flag.

Most of Rosberg's wins have come from the front. People such as Hamilton and Alonso can win from behind as well.

If Alonso was in the second Mercedes instead of Rosberg, this title battle would be a hell of a lot closer than it is now.

David Coulthard was talking to BBC Sport's Andrew Benson