Sepp Blatter offered few specifics as to the reasons why he announced his impending resignation on Tuesday, only four days after he was reelected to a fifth term as FIFA president.

“While I have a mandate from the membership of FIFA, I do not feel that I have a mandate from the entire world of football – the fans, the players, the clubs, the people who live, breathe and love football as much as we all do at FIFA,” he said at a hastily called news conference in Zurich. “Therefore, I have decided to lay down my mandate at an extraordinary elective Congress. I will continue to exercise my functions as FIFA President until that election.”

Thus we are left to speculate. Here are three possible reasons for Blatter’s sudden announcement.

[FIFA president Sepp Blatter to resign]

1. U.S. prosecutors are about to drop the hammer on Blatter, and he knew it.

In announcing the indictments of a number of high-ranking FIFA officials last week, officials at the U.S. Department of Justice promised that more indictments were likely without mentioning Blatter specifically by name. On Tuesday, soon after Blatter made his announcement, a report surfaced that he is being targeted by American law-enforcement officials.

Blatter could be aware that he faces significant legal trouble in the United States and wanted to step down before this news breaks. However, some legal observers point out that his plan could backfire.

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2. World Cup sponsors were about to take their money and go home.

Some of the world’s biggest companies ponied up major cash to sponsor last year’s World Cup in Brazil, with Adidas, Coca-Cola, Emirates airlines, Hyundai-Kia, Sony and Visa spending a combined $1.4 billion for the right to be called official “FIFA partners.” But in November, Sony announced it would not be renewing its $280 million sponsorship agreement with FIFA, and after last week’s indictments Visa announced it would “reassess our sponsorship” unless FIFA showed signs of reform, with the others making similar comments.

FIFA likely would have had little trouble finding new sponsors (a number of similarly sized companies have smaller World Cup sponsorship deals), but not if Blatter’s name became so toxic that any sponsorship connection would be undesirable. Those companies could have told Blatter and FIFA exactly that.

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3. Blatter caved to threats of a European World Cup boycott.

A World Cup without the traditional European powers would hardly be appointment viewing, both for fans and the sponsors and television networks that spend big money to attach their name to the world’s most-watched sporting event. But a boycott of the 2018 World Cup was exactly what some some soccer officials in Europe — where support for Blatter has dwindled over the years — were proposing, going so far as to meet Friday in Berlin to talk about the idea of staging a competing tournament featuring European teams with perhaps some South American powers sprinkled in.

It was seen as a long shot — UEFA was not a united bloc in Friday’s FIFA presidential election, with powers such as France and Spain reportedly voting in Blatter’s favor — but perhaps there was more support for the idea than initially thought.

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