Barry Rithholtz has a post where he notes that a number of economic advisers are warning about a variety of warlike conditions. And by warlike, they mean the of the potentially Roman (presumably IIII) type.
Top Economic Advisers Forecast War and Unrest
Barry Rithholtz, Big Picture, 13 April 2013
I am not impressed. A lot of hand waving. Roubini saying that the Great Depression lead to World War 2 is a little bit like saying that anything that occurs after something else is caused by it. Mother's milk (or formulu) is to blame for everything.
The "Chart of War" is stunning. It lists an oversized backwater war (Vietnam) and ignores a war with direct fighting between today's super powers (Korean War) which happens to be at an up-peak, or the major round of wars in 1905 (Beor War, and Russo-Japanese) that are at a mid-peak.
The really big wars as often as not seem start in some back corner world and seem inevitable only in retrospect. The Seven Years War ,which in total was 9 year long, and is often stated as the first global war, started in the outback of the U.S. Colonies in what we call the French and Indian War.
Note, the name The Nine Years War, was already taken, and the Central European part, with Frederick the Great, was seven years. It is odd to think of Frederick the Great, and George Washington fighting on allied sides during a "World War": but they did. George Washington helped get it started, and I guess you could say, Frederick finished it.