Thing is, I don't necessarily buy the original authors assertion. It's just that there are lots of other things that could easily have an effect, such as investor mood, government spending tie-ins like growing debt (or debt ratio) and inflation, diversion of investor money from things with higher growth potential into things that have immediate profits, like Xe...

None of those necessarily have a great deal to do with troop strength, but they do all seem to correlate with (some) wars.