The F1 team-mates verging on civil war

'Whatever you do, don't drive into your team-mate' is one of Formula 1's abiding principles, something akin to a commandment of grand prix racing. Race as hard as you want or need, but don't let your personal ambition jeopardise the team.

This became an epitaph for the battles for the Formula 1 world championships that defined the past three seasons, as Mercedes team-mates Lewis Hamilton and Nico Rosberg fought tooth and nail for their sport's ultimate prize.

The degeneration of their working relationship - from what Mercedes team boss Toto Wolff calls "friendship to rivalry, rivalry to controversy, controversy to animosity" - can be charted through a sequence of on-track clashes that eventually rendered their relationship almost untenable, creating huge management problems for their team.

A steady escalation of hostilities began with a thrilling wheel-to-wheel battle at the 2014 Bahrain Grand Prix, but subsequent disagreements that year over engine-setting strategies, qualifying controversy, and team orders, created antagonism in their rivalry that culminated in Rosberg taking Hamilton out in Belgium.

The following season, Hamilton dominated the championship, but also drove Rosberg off the circuit a couple of times - rubbing his face in the dirt, and rubbing salt into a very old 'Rosberg's a soft touch' wound. Minor controversies maybe, but they left a lasting impression.

By 2016, they were into full-blown animosity - banging wheels in Melbourne, colliding spectacularly on the first lap at Barcelona, and again while battling for the lead on the last lap at the Red Bull Ring. By the end of the season, Hamilton was wilfully ignoring his team's instructions, racing purely for himself as Mercedes pleaded with him to speed up in Abu Dhabi as he and Rosberg fought for the title.

Mercedes faced the prospect of two more years trying to manage what looked to be an increasingly irrevocable internal dynamic, until Rosberg unexpectedly retired over the winter and allowed the team to push the reset button.

A welcome change of regulation and team-mate means the focus for Hamilton and Mercedes is now - for the moment at least - outward, on Sebastian Vettel and Ferrari. Harmony is the new watchword at Brackley, a balm to sooth the sores left by previous strife.

In fact, unless the safety car is involved, or F1's two Finnish drivers try to occupy the same piece of track simultaneously, the fight for this year's championship is shorn of the sort of hostility that characterised the previous title battles of F1's V6 era.

Of course, the controversies of 2014-16 were thrown into sharper relief by the fact that Hamilton and Rosberg were consistently fighting an exclusive battle between themselves for the world championship.

The internal hostilities between Alain Prost and Ayrton Senna at McLaren in 1989, Nelson Piquet and Nigel Mansell at Williams in '86, or Didier Pironi and Gilles Villeneuve at Ferrari in '82, come instantly to mind because of what was at stake for the protagonists.

But this sort of hostile dynamic is not unique to the front of the grid. This season, there are three teams facing internal battles to keep lids on boiling pots that might send vitriol spilling out into the open at any minute.

Force India has had to lay down the law to Sergio Perez and Esteban Ocon recently, following a collision at the Azerbaijan Grand Prix that cost the team a likely podium finish and a bucketload of points.

Sauber team-mates Marcus Ericsson and Pascal Wehrlein have clashed in two of the past three races while battling on track; and relations between Carlos Sainz Jr and Daniil Kvyat seem to have plumbed new depths following a high-speed tangle that took Sainz out of the British Grand Prix.

The common thread linking these individual dynamics within different teams is relatively immature F1 careers reaching pivotal moments, with drivers needing to prove their worth to earn promotion - or at the very least survival.

In Ocon, Force India has Mercedes' answer to Max Verstappen. Ocon beat Verstappen to the 2014 European Formula 3 title, is rated faster than Red Bull's prodigy by Prema F3 team boss Rene Rosin, and is every bit as ruthless and uncompromising in battle. Ocon is out to prove he has what it takes to go all the way to the top in F1.

Team-mate Perez is looking to take a step back into the big time, having spent the past three-and-a-half seasons rebuilding a reputation battered by a difficult 2013 campaign at McLaren. Perez needs to put Ocon in his place to ensure he isn't overlooked by the top teams again.

Wehrlein was rejected by Force India in favour of Ocon at the end of last season, so needs to do well at Sauber this year to prove he should not be passed up again. Ericsson knows he needs to beat Wehrlein to get taken seriously as an F1 driver, deserving of a shot with a bigger team than Sauber.

Over at Toro Rosso, Sainz is trying to show that he should be considered more than just a back-up option for Red Bull - waiting in the wings in case something happens to disrupt the A-team's current line-up. Team-mate Kvyat is still fighting for his life in F1, after getting dumped out of Red Bull to make way for Verstappen following the first four races of 2016.

These team-mate dynamics feature a particularly combustive mix of drivers, some scorned and derided, all trying to realise their talent and ambition, with points to prove - both to themselves and their respective paymasters.

That's true of any team, of course, but contrast these particular scenarios with the harmony between Hamilton and Valtteri Bottas at Mercedes; the friendship between Vettel and Kimi Raikkonen at Ferrari; the mutual respect between Daniel Ricciardo and Max Verstappen at Red Bull (helped by Ricciardo's easygoing nature); Stoffel Vandoorne's reverence of Fernando Alonso at McLaren-Honda; the new 'he's the fastest team-mate I've ever had' love-in between Romain Grosjean and Kevin Magnussen at Haas; the parent-teacher relationship between veteran Felipe Massa and rookie Lance Stroll at Williams; and Nico Hulkenberg's utter domination of Jolyon Palmer at Renault.

These other teams aren't facing the same internal pressures that have surfaced recently at Force India, Toro Rosso and - to a lesser extent - Sauber.

Are these small outfits equipped to deal with such extra stress? Force India seems to be revelling in having a 'top team problem' such as this, but managing it is difficult when Perez brings commercial backing to the team. How do you tell a guy whose sponsors are adding several million dollars of support to your bottom line to move aside for his faster team-mate in the interests of the greater good?

The answer is: you can't. So, Force India will have to rely on the drivers to sort it out between themselves. They certainly disagreed over who was at fault for what happened in Azerbaijan, so we will only learn of their resolution when they go wheel-to-wheel with each other again.

Sauber has been here before quite recently, when Ericsson and Felipe Nasr drove into each other at the 2015 Monaco GP. Former team principal Monisha Kaltenborn read them the riot act and there was no repeat.

But in that instance both were fresh-faced rookies. Kaltenborn is gone now, Ericsson is a third-year driver, and both he and Wehrlein have a lot to prove this year. New boss Frederic Vasseur says his priority is sorting out Sauber's engine supply for 2018, but he's also going to need to watch out for his drivers.

Ericsson and Wehrlein banged wheels in Baku, before Ericsson was asked to move aside for fear the battle would cost Sauber a point to Vandoorne, while Ericsson felt Wehrlein failed to give him enough racing room during their battling at Silverstone.

So far relations remain cordial, with Ericsson describing the recent racing between the two as hard but fair. Of this triumvirate of teams, Sauber has the least degree of internal stress between the drivers at the moment, but we'll see if that continues should they come to blows again.

Toro Rosso had some trouble at the start of 2016, which Verstappen's promotion to Red Bull after four races helped diffuse - along with some shuffling of personnel inside the team. Sainz and Kvyat share a competitive history that traces its roots all the way back to karting, echoing the sort of dynamic that eventually undid Hamilton and Rosberg.

Sainz has kept his counsel following the incident that took him out of the British GP, but Kvyat feels Sainz got away with transgressions earlier in the season and sees no point in discussing things with his team-mate, saying their relationship has "never been fantastic, really. I don't expect anything to change."

Toro Rosso's situation is complicated by being in a tight fight for fifth in the constructors' championship, and by the fact that parent company Red Bull has indicated it wants to keep the same line-up in place for 2018. That's probably going to require some strong management by the likes of Franz Tost and James Key.

They would do well to sit down with Toto Wolff and ask him how best to approach things. He'll no doubt tell them events at Mercedes over the previous three years prove it can be done. But Wolff now knows better than most that avoiding all-out civil war as a team-mate rivalry escalates bitterly is just about the hardest job in F1.