If you're not East African, you're not going to win the 800m at the Olympics. Facts
20-25 years ago they were saying that 800m was the only distance non-Africans had a chance at.
What sense does that make? How did non-Africans crush everything from 60 meters to the marathon then...in the past 20-25 yrs?
The evidence at the time was pretty good. Coe's record had withstood years where Africans could attack it and then three white guys won the Olympic 800. It seems reasonable that the statement was accurate.
Non-Africans haven't been dominating like you seem to suggest They may be showing that they can still be relevant.