JUDY WOODRUFF: Just four days after he won reelection to a fifth term as the head of soccer's international governing body, Sepp Blatter stunned nearly everyone today when he announced he would resign as president of FIFA. Top FIFA officials were arrested last week.

The Department of Justice uncorked a 47-count indictment alleging bribery and widespread corruption. And, yesterday, published reports said Blatter's top deputy had been linked to wire transfers involving bank payments believed to be bribes related to World Cup bids.

At a hastily called news conference today, Blatter didn't address the specifics, but acknowledged the mounting scandal undercut the votes and the mandate he said he received last week.

JOSEPH "SEPP" BLATTER, President, FIFA (through interpreter): This mandate doesn't seem to be supported by everybody in the world of football, supporters, clubs, players, those who inspire life in football, as much as we do at FIFA. That's why I will call an extraordinary congress and put at disposal my function. It is going to be held as soon as possible and a new president will be elected to follow me.

JUDY WOODRUFF: Let's look at the sudden resignation and the circumstances around it.

Declan Hill is an investigative journalist and the author of a book about FIFA's problems with corruption. It's called "The Fix: Soccer and Organized Crime." I spoke with him a short time ago from Ottawa.

Declan Hill, welcome.

So, why the sudden reversal? Sepp Blatter said just on Friday that he was glad to be reelected and this was going to be a new era for FIFA.

DECLAN HILL, Author, "The Fix: Soccer and Organized Crime": It really is extraordinary.

I mean, today's events starting early Zurich time dawn all the way to right now is an epic, shaking time in international sports. It reminds me a little bit of "Game of Thrones," the Lannisters are meeting at King's Landing.

And what is really going on is a bunch of kingmakers, people behind the throne, people that we don't see in public, either as the journalists or as sports fans, I think phoned up Sepp Blatter this morning and said enough is enough.

JUDY WOODRUFF: So, what precipitated that? As you and I are speaking, as we tape this interview, ABC News is reporting that the FBI, U.S. prosecutors are now investigating Blatter himself.

DECLAN HILL: Yes, and you have an extraordinary scenario here.

As you can see, I'm speaking to you from Ottawa, Canada, where the women's World Cup will be in a few days. The second in command today earlier today in Zurich suddenly discovered that he had crucial business that meant he couldn't fly to Canada. Really, what may be going on, and a lot of people are talking about this, is that he's afraid of landing in Canada.

Canadian extradition laws with the United States are excellent, and if you guys want people arrested, our police services generally arrest them and extradite them right way, unlike Switzerland or Trinidad and Tobago.

So, there was a fear that the top executives couldn't even attend the women's World Cup without fear of being arrested. This is really extraordinary.

JUDY WOODRUFF: Is there a sense, Declan Hill, of who else may be implicated before this is over?

DECLAN HILL: Yes, I looked at the FBI indictment that came out, as you know, under Loretta Lynch, the attorney general, last week, and it's an extraordinary picture.

What they really paint is a deliberate, clear, informal organized crime syndicate operating inside international sports. So you have the public face of how to market these TV, all these ticketing things, and then you have these really meticulous, well-planned scams that are going on inside that organization. So, really, if you're getting the second in command who is afraid of getting on a plane to fly to Canada, it really could be anyone.

JUDY WOODRUFF: So, for Blatter to step down and be replaced by someone else, how much of a change is that in and of itself?

DECLAN HILL: I think it's really an era-making change.

There's a whole bunch of national sports federations around the world or soccer federations that are going to be deeply, deeply worried. Look, FIFA has a track record of, when national governments, be they Iran, be they Greece, be they Kenya, be they Nigeria, look at their soccer and say, hang on, if this is too corrupt, we're going to clean it up.

FIFA will go in and stop those government investigations. They will stop those police investigations and they will say, hey, you know, you can't investigate our people, because that's politics interfering with sport.

So you have sports, soccer federations around the world that have been essentially protected by Blatter and the people in Zurich. That day seems to be over now, and that's going to shake the soccer world in a tremendous way.

JUDY WOODRUFF: Declan Hill, we thank you very much for talking with us.

DECLAN HILL: Thanks for having me on, Judy. Very much appreciate it.