Nick B., who occasionally writes about statistical graphics, found some classic chart junk from a Canadian report on the Afghan army. Here's one example, together with the junkchart version.
Redundancy is an enemy of good graphics, and incongruous redundancy is worse. Here, troop level is variously described as "total force size", "strength" and "army growth"; the chart on the right uses only the army concept. The data labels ("47000 Strength"), the axis labels ("50000 Total Force Size"), and the gridlines all germinate from the five grand data points underlying the entire chart!
Another distorting feature is that use of different-sized time intervals, which we space out appropriately on the right chart.
Ultimately, the key message should be growth in the army size, not the absolute number of troops. The slopes of the line segments encode this information. Alternatively, a data table can be rather powerful for simple data like this: