Today, the International Olympic Committee agreed, but added one significant loophole.

　　John Yang has that story.

　　JOHN YANG: The IAAF decision was unprecedented in Olympic history. Russian President Vladimir Putin slammed it as unfair collective punishment.

　　Today's move by the IOC seems to send a contradictory signal. On the one hand, the IOC did uphold the ban. But it also said that Russia's track and field athletes could participate if they pass follow-up drug tests administered in other countries.

　　There is a lot of confused reaction to all of this.

　　And to help us understand it all, Christine Brennan is back with us. She's a sportswriter, columnist and commentator with USA Today and ABC News.

　　Christine, this is very confusing. On the one hand, they uphold the ban, and they say that the IAAF was — they respected their right to impose the ban. But they also opened the door for athletes to compete. How does this work?

　　普京是否要为国际奥委会禁赛运动员负责?

　　CHRISTINE BRENNAN, USA Today: Oh, it's going to be confusion.

　　I have never seen — I have covered the Olympics, John, for 32 years. I have never seen anything like this. We're six weeks out from the Rio opening ceremonies, and this could be a situation where we don't know who is marching in under the Russian flag or the Olympic flag in terms of athletes, track and field athletes from Russia, until they march in, in the opening ceremony.

　　This is a battle right now we're seeing between the IOC and the International Track and Field Federation. We have never seen anything quite like this.

　　JOHN YANG: Why is this going on? Why are these two organizations battling this out?

　　CHRISTINE BRENNAN: Can I blame it on Vladimir Putin?

　　He — Putin put an Olympics in the middle of nowhere, spent $51 billion — billion with a B — dollars to do that. And I think that we're talking about an old boys' network here, very old boys' network, with the IOC. Think FIFA.

　　And Putin did them a big favor to the tune of $51 billion, John. And there is no doubt Putin has a voice and has a say within the International Olympic Committee. If they had just said no Russian athletes at all, the IOC has said this, which is what the IAAF has basically said — the IAAF has gone against Putin.

　　The International Olympic Committee has left the door open a crack, and that is all because Putin bailed them out two years ago.

　　JOHN YANG: And we should point out that the IOC publicly says they're doing this because the presumption of innocence of these athletes is being damaged.

　　CHRISTINE BRENNAN: Right, but — right. We weren't born yesterday in terms of the politics of international sport.

　　I will say this. The idea of having clean athletes at the Olympics, the Russian system is rotten to the core. That is what we have seen over and over again. The World Anti-Doping Agency saying you cannot trust anyone who has gone through the doping system in Russia. And so the idea of having — finding clean athletes, you would almost need a time machine to go back a couple years and test them under, say, U.S. or Western European rules.

　　And because we can't trust the Russian system, and what they have been doing, their doping facilities, I don't know how we're going to — they're going to get clean results for these athletes in six weeks. You will see someone, say, who ran the New York City Marathon, well, if they had a clean test there, OK, that's one.

　　But that's certainly wouldn't — I don't think would give us any confidence that that athlete has been clean for the last couple of years.

　　JOHN YANG: So, do we know how they're going to try to prove their innocence and how — what the IOC has in mind when they say they have got to pass these follow-up tests?

　　CHRISTINE BRENNAN: I think the endgame here is that they are going to want to get some Russian athletes into the Olympics.

　　And, again, I know this sounds like cloak and dagger and like some kind of Bond movie, but I really think we're there with this, because of this incredible, unprecedented battle between these two powerful organizations.

　　The fact that you have got the track and field athletes, you have also got Russian swimmers, John, and several others. There's another report coming out in mid-July about the state-sponsored systemic doping among the Russian athletes. So, at that point, you might hear the cry to have the Russian athletes be completely kicked out of the Olympic Games.

　　But that's only two weeks before Rio. I think what we could see happening is many more Russian athletes than we even think about right now being allowed in, only because they're going to run out of time to prove that they're guilty.

　　JOHN YANG: We have got less than a minute left, and we have got all sorts of issues surrounding the Rio Olympics.

　　We're less than six weeks away. You have the Zika virus. You have got questions about health and safety down there. And now you have got this. Is there a big cloud that's going to be over these Games?

　　CHRISTINE BRENNAN: There could be unlike any other Olympics.

　　Usually, there's always something that you think about, terrorism in Sochi or terrorism in Athens, a home game for the terrorists at the Olympics in Athens in '04, and then nothing bad happens.

　　The question here is maybe will Rio be that first Olympic city to be consumed by the Olympic Games? Because, as you said, so many things on their plate. And then you throw in this Russian controversy. And I hope that's not the case, but I think Rio might really be that first Olympic city to have real trouble hosting the Games.

　　JOHN YANG: Two months away. We will see what happens.

　　Christine Brennan, thanks so much for being with us.

　　CHRISTINE BRENNAN: Thank you, John.