There are some occasions when you have to make a choice between two vastly different directions. When you make a decision which, while related to one specific issue, will have wide-ranging repercussions that will be felt for generations to come.

Britain is facing one such moment on Thursday (June 23) when a referendum will be held on whether to remain a member of the European Union. I don’t think it as an exaggeration to describe last week’s International Association of Athletics Federations (IAAF) decision to extend Russia’s spell in the track and field wilderness as another.

It was clear heading into the meeting that, despite the best efforts of Sports Minister Vitaly Mutko and a public relations campaign spearheaded by American public relations giants Burston-Marsteller, no one really believed that Russia had cleaned-up their doping system in the eight months since non-compliance was first declared. A World Anti-Doping Agency (WADA) report published two days before the meeting seemed to end any prospect of this.

Armed secret police banning access to military cities, a bungled attempt to switch urine samples before an equally unsuccessful effort to bribe testers, and athletes running away - quite literally - once the inspectors arrived were three of the more damning titbits.

Yet still, we could not be sure that there was not going to be some sort of cop-out and concession to the mighty diplomatic sway of the world’s largest country. And if the IAAF did act, some wondered, could the International Olympic Committee (IOC) step-in and overrule them?

When the verdict was finally confirmed after several hours of rumours trickling out of the Congress room, the initial reaction was that it had indeed been a cop-out. Russian athletes would be allowed to participate under an independent flag in Rio, we were told, so long as they can prove they have been operating in an effective drug-testing system.

But it gradually became clear that this rule change was introduced to please the lawyers more than the Kremlin.

For by having a clear avenue by which to apply, it will make it far harder for successful appeals to be launched against the ban. Andersen, a softly-spoken giant from Norway who was the real star of the show, reiterated how simply being a “clean athlete” was not enough. Anyone based in Russia and therefore to the Russian testing regime, or lack thereof, would be presumed to be doping. So only those based outside the country will have a realistic chance, meaning it is likely to be “three, four, a handful” at most.

One of these will almost certainly be Yuliya Stepanova, the doping cheat turned whistleblower whose allegations began a chain of events culminating in the IAAF decision. But this decision can be criticised because after all she did dope, so should she be given special dispensation? But, as Andersen pointed-out, you have to reward whistleblowers in order to encourage them to come forward. Sports bodies like WADA and the IAAF are belatedly beginning to understand this. Stepanova aside, the only other name floating around so far is glamorous long jumper Darya Klishina, who has spent time based in the US. Big names like pole vaulter Yelena Isinbayeva and 110 metres hurdles world champion Sergey Shubenkov are thought to be ruled-out, and we can certainly expect few medals to be won.

Yet there are far deeper ramifications than simply a lack of a Russian presence in Rio. By saying that no Russian-based athletes can be considered clean, Andersen is essentially dismissing the doctrine of innocent-until-proven-guilty. It is now the responsibility of the athlete to prove they are clean by subjecting themselves to effective testing.

In a way this has always been the case in anti-doping. In what other field would you get a 6am visit from a drug tester extracting a urine sample when there is not the slightest shred of evidence against you? A spot-test for drink-driving, perhaps, but this is different from how crime is assessed in the real world.

But it now sets a fascinating precedent. How are Russian athletes “clean” in other sports? Do we need specific allegations made against every single one before a blanket suspension, or, as WADA President Sir Craig Reedie has mooted today, would the confirmation of the remarkable allegations of state sponsored doping at Sochi 2014 be enough?

And what about other countries? Other Soviet bloc states where similar systems are rumoured, or others lacking WADA compliance, like Mexico and Kenya? Where do we stop? Could we have an Olympics lacking 20 to 30 per cent of the world countries? What impact could this have to the Olympic brand?

If, as expected, the IOC continues to support the IAAF stance at its Summit here tomorrow, could the Russians even respond with a full-blown boycott, dragging along some of their loyal neighbours with them? This seems unlikely at this stage, but must be a concern. And it is these countries who are some of the only willing hosts for many sporting events.

Those old enough to remember the Olympic boycotts of 1976, 1980 and 1984 seem particularly opposed to any ban on participation, and it is true, that a door, firmly shut for several decades, has been pushed slightly ajar again.

When studying US politics, we learnt about seminal legal cases like Brown versus Board on racial segregation and Roe v Wade on abortions. Could this prove just as significant in a sporting sense?

But in another way this makes the decision all the better. For once, sport decided against turning a blind eye in order to continue a stress-free life. The decision may cause challenges down the line, but it also delivered a clear message that doping will not be tolerated; and that had to be made.

In endorsing the IAAF and promising “far-reaching measures” to show their “zero-tolerance” approach, the IOC have taken a similar view. But only belatedly, and, while it seems impossible that they did not know of the IAAF decision beforehand, they do seem to have been out-manoeuvred by the world governing body.

Another point here is a possible reshuffling of the balance of power between the IOC and the IAAF. “For too long we have been inferior to the IOC,” one aide muttered last week. “This decision showed we can act independently.”

The IAAF certainly doesn’t deserve wholehearted praise. Just like the IOC reacted to their decision, they had little choice but to react to WADA, who, in turn, had little option but to react to a coalition of whistleblowers and journalists who made the revelations in the first place. Sporting administrators still have a lot to do to really prove tackling drugs in sport is their number one priority.

But this decision was a start. Russia can protest it all likes - calling for the IAAF to be disbanded in another of those fit of piques which is actually now harming their defence - but the decision was necessary and vital if doping in sport is ever to be truly eradicated.