history is composed not only of what our best guess is of what happened, but how that guess came to be and changed over time. my experience of studying modern history is that the biggest missing piece seems to be knowledge of where intellectual and political trends originated from and how they propagated. the information is there, but it is buried among many primary texts and largely ignored by "story centric" history. I don't blame historians for doing this, they must make history sexy or risk being considered irrelevant.