USADA chief Travis Tygart told AFP in an interview that a year dogged by scandal had presented authorities with a window of opportunity to get tough and reform -- or risk a backlash from frustrated clean athletes if they failed to do so.
"On the one hand, it has been a challenging year but on the other hand, being on the brink of holding state-supported doping to account is exactly what needs to happen," Tygart told AFP.
"It presents a defining moment, but that window is about to close. We have to get sport off of its solidified power position to make the necessary reforms to ensure that we're never in this situation again."
Tygart was speaking to AFP ahead of the release on Friday of a report by Canadian law professor Richard McLaren expected to lift the lid once more on doping in Russia.
The first instalment of McLaren's report, ordered by the World Anti-Doping Agency, detailed a sophisticated state-backed scheme in Russia to rig drug tests at the 2014 Sochi Winter Olympics and Paralympics.
Tygart believes a failure to act decisively against Russia could have disastrous consequences for the future of clean sport.
"Clean athletes are watching. They are very frustrated and even angry at what has occurred in a powerful country that has had tremendous success in international competitions, that could be running a doping program at the extent as it did," he said.
"If the change is not put in place to ensure that doesn't ever happen again, those athletes are either going to revolt or they are just going to join the dopers. That's unacceptable."
Previous investigations published this year had shown "beyond any doubt...that the sport system in Russia was rotten to the core," Tygart said.
"It corrupted the Olympic Games and it robbed clean athletes. And now those athletes deserve justice. And Russia needs to be held accountable for their actions, he said.
Tygart said the tumultuous events of the past 12 months have highlighted structural flaws of a system which allows for overlap within WADA and the International Olympic Committee, presenting the possibility of a conflict of interest.
The Olympic movement is well represented on both the WADA Foundation Board (18 members) and the agency's executive committee (five members). The fact that WADA's President, Craig Reedie, is also an IOC member, is problematical, Tygart said.
"We have to remove sport from the governance at WADA because there's an inherent conflict of interest," Tygart said.
"It's not personal, it's not based on the individuals, it's positional. You can't simultaneously be an IOC executive board member and be president of WADA.
"Because sometimes you have to make decisions that are the best for clean athletes and their rights that might be against the short-term interests of sport."
Tygart cited the example of USADA's leading role in exposing Lance Armstrong as a doping cheat.
"It would have been like the president of international cycling being on our board at USADA when we held Lance Armstrong and the Postal Service's team accountable because of their cheating," Tygart said.
"You can only imagine that outcome might be different if the president of international cycling was also the president of the US anti-doping organisation."
Giving WADA the power to issue provisional sanctions against countries or individuals would be a step in the right direction, Tygart added.
"Once you change the governance of WADA you obviously have to give them clear authority to investigate and sanction," Tygart said.
"That doesn't mean they're the judge. It just means that they operate like every other democratic organisation that has compliance powers. They put in place the sanction but then that can be appealed to an independent judicial body, the Court of Arbitration for Sport. But WADA absolutely has to have the sanctioning powers."
The oft-cited obstacle to enhancing WADA's investigative reach around the world -- the cost -- could be remedied by the IOC at a stroke if it chose to do so, Tygart believes.
"The IOC could solve the problem today," Tygart said. "They have a $1.4 billion dollar fund. They could take $500 million of that and set it aside in a blind trust to spill off money to fund WADA and the efforts for clean sport," Tygart said.
Failure to invest in enforcing clean sport could ultimately erode revenue streams if fans, sponsors and broadcasters no longer had confidence in the spectacle.
"(The IOC) benefit from having competition on the field that is played by the rules, "Tygart said. "Because at some point, the fans walk away."