On the "Greatest Match that Never Happened" thread, someone brought up Akii-Bua/Moses at 1976 Olympics. That called to mind this story:
Kip Keino's coach once told me that the Ethiopians and the Kenyans - the two African countries with the most to lose from a boycott - had agreed that neither nation would boycott as long as the other held out. Then Kenyan and Ethiopian teams both traveled to Montreal. The night before (or possibly of) the opening ceremonies, the Kenyans received a cable from Nairobi, with the President's name, telling them to boycott. Crushed, they left. And when they left, the Ethiopians were left high and dry, and could not hold out against the pressure to boycott.
That's not the end of the story, however. Upon arrival in Nairobi, the coach asked the President what happened to make him change his mind. He said that he never authorized that cable - but that once the team had announced it was leaving, he couldn't reverse the action without taking an inordinate amount of political heat.
Now, that coach was known for stretching a story on occasion, so who knows how much is true. And even if the story is true, the president's statement at the end could very well have been false. But it's an intriguing story! We almost had Yifter vs Viren, Rono vs Garderud, etc.