My dream is a book/blog explaining historic processes with Ishikawa cause-and-effect fishbone diagrams[0]. For history, the main branches of the fishbone could be: Military, Economy, Society, Politics, and Nature. So a tentative diagram explaining the fall of the Western Roman Empire would have:

* Military: weakened army (increasing dependence on mercenaries), fights with the Germanic tribes (in turn, caused by the expansion of the Huns).

* Economy: inflation (debasement of currency), decline in the influx of slaves (end of expansion), lost taxation from some provinces (Germanic invasions), decline in maritime trade (Vandalic pirates), decline of agriculture (excessive taxes), drain of money (trade deficit with the Eastern Empire).

* Society: decline of civic virtue (expansion of Christianity), loss of ties with Rome in the provinces.

* Politics: political instability, overly powerful Praetorian Guard.

* Nature: population decline (Antonine Plague, Plague of Cyprian), soil erosion (deforestation, excessive grazing, soil salinization).

Improving the diagram and making similar diagrams explaining other events and processes is left as an exercise to the reader.

[0] https://en.wikipedia.org/wiki/Ishikawa_diagram