Further to yesterday's comments on the uneven state of American [men's]distance running; by comparison the Australians (PDF) have no A qualifiers in the 1500, 1 in the 5000, none in the 10000 (where the Americans are surprisingly strong with 6 A qualifiers), 5 in the marathon (8 U.S.), and 1 in the steeples (2 U.S.). New Zealand has 1 1500m qualifier, a 10,000m qualifier and 2 in the marathon.
Now obviously, in small countries these things are somewhat more random, you just don't get exceptional athletes turning up all the time in small populations.
Australia is a good comparator though, precisely because it's smaller than the U.S. but not really small (like New Zealand). 5 qualifiers in the marathon with a population 1/15 the size is a pretty good indicator of the relative strengths of distance running in the two countries.
The real contrast, in both Australia and the U.S. has to be with the swimming programs which are phenomenal. In fact the contrast with swimming suggests that some of the problems are structural -- get a good development program going and keep young people coming through the system and you get lots of people contending for the Olympics, which tends to lead to some of them winning medals and making finals. That just isn't happening systematically in American distance running, but developments like Team USA MN have to be a step in the right direction, with a lot of the athletes involved making pretty rapid downward progress in their times.