Decision time: IOC poised to rule on Russia’s status for Summer Games

London — As the clock ticks down to the opening ceremony in Rio de Janeiro, international Olympic leaders are facing a seminal moment.

With the credibility of the fight against doping on the line and the image of the Olympic movement at stake, the IOC will hold a crucial meeting today to consider whether to ban Russia entirely from the Rio Games because of systematic, state-sponsored cheating.

Short of a blanket ban, the International Olympic Committee could leave it to individual sports federations to decide on a case-by-case basis whether to allow Russian athletes in their events.

The doping crisis represents one of the Olympic movement's biggest challenges since the boycott era of the 1980s, and how it plays out may well define Thomas Bach's IOC presidency.

The IOC's ruling 15-member executive board will meet via teleconference to weigh the unprecedented step of excluding Russia as a whole from the games. Bach and others have spoken of a need to balance "individual justice" versus "collective punishment."

Time is of the essence, with the games set to open in Rio on Aug. 5.

Russia's track and field athletes have already been banned by the IAAF, the sport's governing body, following allegations of state-directed doping — a decision that was upheld Thursday by the Court of Arbitration for Sport.

Calls for a complete ban on Russia have intensified since Monday when Richard McLaren, a Canadian lawyer commissioned by the World Anti-Doping Agency, issued a report accusing Russia's sports ministry of overseeing a vast doping program of its Olympic athletes.

McLaren's investigation, based heavily on evidence from former Moscow doping lab director Grigory Rodchenkov, affirmed allegations of brazen manipulation of Russian urine samples at the 2014 Winter Games in Sochi, but also found that state-backed doping had involved 28 summer and winter sports from 2011 to 2015.

Bach said the findings showed a "shocking and unprecedented attack on the integrity of sports and on the Olympic Games" and declared the IOC "will not hesitate to take the toughest sanctions available against any individual or organization implicated."

Russia also faces a possible ban from the Paralympic Games. Citing evidence in McLaren's report of doping among Russian Paralympic athletes, the International Paralympic Committee said Friday it will decide next month whether to exclude the country from the Sept. 7-18 event, also in Rio.