Travis Tygart, the chief executive of the United States Anti-Doping Agency, has accused International Olympic Committee (IOC) President Thomas Bach of "throwing in the towel" after he conceded that sport's battle against drugs cannot be won.
The German told CNN Switzerland earlier this month that "doping will always happen".
"This is one of the wars you cannot win," he added.
Tygart criticised this stance and said it was comparable to Olympic athletes not trying in their events.
"It's obviously a tough fight but the leader of sport can't simply throw in the towel," said Tygart to CNN World Sport.
"Can you imagine if Michael Phelps or Usain Bolt walked into an Olympic final and said 'I can't win this?'
"It's not the focus, it's not the determination and it's not the commitment that clean athletes expect and deserve."
Tygart also warned against the World Anti-Doping Agency (WADA) Executive Committee reinstating Russia at a key meeting in the Seychelles on September 20.
The Russian Anti-Doping Agency (RUSADA) has been non-compliant with WADA since 2015 when allegations of state sponsored doping in the country first emerged.
Russia has since been accused of the systematic manipulation of the doping system at their home Sochi 2014 Winter Olympics, with the IOC forcing them to compete under a neutral flag at Pyeongchang 2018 in February.
The country remains suspended by the International Association of Athletics Federations (IAAF) and the International Paralympic Committee (IPC), but the IOC's ban on the Russian Olympic Committee was lifted immediately after Pyeongchang.
Figures from within sport are keen to allow Russia back into the fold despite two outstanding criteria on WADA's roadmap for RUSADA's re-acceptance not being met.
These are an acceptance of the McLaren Report, which outlined much of the evidence against Russia, and full access to the Moscow Laboratory.
No side has backed down so far with the situation in a state of deadlock.
Tygart, a vocal critic of Russia, said Bach's comments could be a sign that RUSADA will be allowed back in the Seychelles.
"Maybe it's a prediction that they are going to do that," he said to CNN.
"It's a staredown right now, quite frankly, between Russia and WADA.
"I think that unfortunately that if WADA blinks, and allows Russia to be reinstated, despite not fulfilling the two remaining conditions of the roadmap, it will be the U-turn of all U-turns.
"It will be a devastating blow to WADA's credibility as well as to the hopes and dreams of millions of athletes around the world who believe in clean and fair competition."
If RUSADA are reinstated it would pave the way for similar moves at the IAAF and IPC.
"They [Sports Movement] have been trying to draw a line under it and bring back one of the biggest countries in the Olympic Movement," Tygart added.
"They are attempting to put it in the rear-view mirror but the truth can't be easily suppressed.
"We can't just wipe the slate clean without putting meaningful consequences in place.
"The trust athletes have in the system is on life support.
"Let's hope the decision doesn't happen but if it does, we're going to do everything possible to not let athletes throw in the towel and continue to have them believe in clean sport.
"And even when the sports promoters let them down, it's not time to quit."