If a deflationary wave sweeps across the globe, our debt saturated world will shatter and a global depression will create economic havoc and lead to a catastrophic outcome. This would lead countries to lash out militarily to either distract their suffering citizens or to seek retribution against countries they feel have wronged them.
The military build-up in countries across the globe in the last ten years has created a global powder-keg, with lunatic leaders lighting matches.
Extreme economic distress always leads to war.