I don't think you can call them "previous" just yet. It's entirely possible for the world to erupt into a ww3, simply due to hundreds of millions of seriously unemployed people. Arguably that was the reason for ww1 as well as huge number of people were made redundant in agriculture.
It was also the reason for WW2. Germany put all those unemployed people to work on many national projects. Projects which were aimed at world domination.
All this was before unemployed people could spend 12 hours a day killing people in Call Of Duty 4, though. I think the availability of cheap distraction (interactive distraction at that) might have some effect here.
It's frightening to think about that.