By Dan Roan-BBC sports editor
The eyes of the sporting world will be on the International Olympic Committee’s headquarters in Lausanne on Tuesday evening when President Thomas Bach announces whether he and his board have banned Russia from the 2018 Winter Olympics.
For an Olympic powerhouse nation, the hosts of the next football World Cup no less, to be cast as an international sporting pariah, would be unprecedented.
But just 66 days before Pyeongchang 2018 starts on 9 February, the signs point to Bach doing precisely that.
The German and his board will have spent the afternoon poring over the findings and recommendations of a 16-month investigation headed up by the former president of Switzerland, Samuel Schmid.
His team have been looking into the allegations of government involvement in the cheating when Russia hosted the last Winter Games in Sochi in 2014, and deciding whether there is enough evidence to conclude that this is indeed what happened, despite repeated denials.
Certainly this is one of the biggest decisions the IOC has ever taken, and the most important moment yet in the doping saga that has cast a shadow over the Olympic movement.
We have been here before, of course.
On the eve of the 2016 Rio Games, the IOC came under huge pressure to ban the Russian team from the Olympics after an independent report by Canadian law professor Richard McLaren concluded the country had engaged in a state-sponsored doping conspiracy that benefitted 1,000 athletes across 30 sports between 2012 and 2015.
Despite this, the IOC could not bring itself to do so, handing responsibility for sanctions to the various international sporting federations, meaning hundreds of athletes competed, and 56 medals were won.
So why should things be any different this time around?
Despite initial fears that Bach’s close relationship with Russian President Vladimir Putin – and a lack of proof that would satisfy legal requirements – may mean the IOC could try to swerve a ban and resort to a hefty fine as an alternative means of punishing Russia, matters first started to look bleak for the country last month.
That was when the World Anti-Doping Agency (Wada) decided the country’s anti-doping agency Rusada was still non-compliant with its rules.
IOC is at a ‘real tipping point’ – Pound
This was accompanied by a breakthrough in evidence, with Wada obtaining what it said was a Russian laboratory database which it felt corroborated McLaren’s conclusions.
Re-tests of Russian athletes’ samples, meanwhile, resulted in a host of retrospective bans and stripping of medals, costing the country its position at the top of the Sochi 2014 medal table.
Twenty five Russians have now been banned in the last month.
And then, last week, another IOC commission, led by Swiss lawyer Denis Oswald, which has been looking into re-tests of samples from Sochi and the individual cases of alleged doping, crucially gave its full backing to evidence provided by Dr Grigory Rodchenkov, the key whistleblower in the scandal, describing him as a “truthful witness”.
Having published its reasoned decision in the case of the cross-country skier Alexander Legkov, the commission also revealed a diary kept by Rodchenkov – the former head of the Wada-accredited anti-doping laboratories in Moscow and Sochi and a central figure in the conspiracy – was also described as “significant evidence”.
The diary detailed alleged meetings Rodchenkov says he had with Russia’s Deputy Prime Minister and former Sports Minister Vitaly Mutko to discuss the doping programme.
Mutko has always denied being involved, vehemently rejected the suggestion that the cheating was in any way state-sponsored, and has cast the saga as a Western conspiracy, unfairly singling out Russia.
The stakes are extremely high in Lausanne.
Despite a denial on Monday from a Kremlin spokesman, some observers believe that if the IOC follows the example set by athletics’ governing body the IAAF and the International Paralympic Committee, both of which only allowed Russian athletes who could prove they were clean to compete as neutrals at the 2016 Olympics and Paralympics, there could be a boycott.
With his country’s presidential election looming next year, Putin may not tolerate the idea of an Olympics with no Russian flag or anthem, and order his athletes to stay at home, rather than compete under a white flag.
Bach, already under significant pressure from national anti-doping agencies to come down heavily on Russia, and aware of the need to be seen to act decisively and in the interests of the future of the Olympic movement following recent IOC corruption allegations, could now be ready to take that risk.
Plenty of Russians would be dismayed by such an outcome.
It’s important for yourself and your country to see your own flag – Svetlana Zhurova
“It would be unfair,” former Olympic speed-skating champion and politician Svetlana Zhurova told BBC Sport from her office in the Duma, the Russian parliament.
“I cannot advise the IOC, they know better than me, but I hope they will remember about the young and clean athletes for whom this will be their first Games.
“You feel so proud when you see your flag, it’s very important for yourself and your country. It has to be individual responsibility, not collective.
“Our anti-doping programmes and legislation have improved. Things have changed a lot and everyone in Russia understands that doping is evil.
“For any sport, it’s very important that all countries are there and if you win you know you are the best in the world. For the IOC it’s a very hard decision and I hope they calculate and make the right decision for innocent clean, Russian athletes.”
Others, however, disagree.
Former Wada president Dick Pound told the BBC: “I think it’s a real tipping point, you’ve got to walk the walk as well as to talk the talk. You can’t say we’re at zero tolerance for doping in Olympic sport … unless it’s Russia.
“I mean your credibility is shot so they’ve got to say we’re a principle organisation, here are the facts, the conduct was unacceptable and a country acting in that manner should not be allowed to participate in the next Games.
“I think we missed an opportunity in Rio… Certainly all the recent indications are there will be strong action… this stuff in Sochi was a direct attack on the integrity of the Olympic Games and the IOC president has recently been starting to focus in on that and saying this is a direct attack on the integrity of the world’s most important international competition, there will have to be strong measures.
“We’ll see whether he follows through.”
Last week in Moscow, as Russia tried desperately to focus on the prestige that comes with hosting the World Cup, and football’s world governing body Fifa attempted to pretend none of this mattered to the credibility of their flagship event, I managed to ask Mutko directly if he expected Russia to be banned by the IOC, just four days after the draw.
He angrily suggested that the BBC and New York Times would know before him, and then suggested Russia was being unfairly criticised by the Western media, just like it was before the Sochi Games.
He spoke like a man who suspected that Russia may have run out of chances.