Jesus Colin, was that the "i dont have a dream" speech?
I think we are certainly fighting much less today than at any point in history. mostly there are just "conflicts" here and there. i think there are a few very important differences in conflict today and conflict in the past that make the likelyhood of fighting in the future to be substantially less that fighting in the past.
information
globalization
weapons
with speed of light access to information world wide, conflicts can only get smaller and smaller. its is highly unlikely that another Hitler can exist on the same scales of the past. It is no longer possible to manipulate and control the information people receive, which in turn can shape their opions in a favorable way.
Globalization is good for encouraging an increasing inter-dependence of countries of each other. What kept China from going right off the deep in the end of the last century for example? Their dependence on exports of Chinese crap to carnivals. We were able to use economic leverage, trade restrictions and even WTO membership as a tool to modify their behavior somewhat.
Weapons are clearly creating a VERY uneven playing field. its not a question of sheer numbers and motivation anymore... or whose sword is sharpest as 100,000 soldiers take the field to face each other. We stopped an atillery shell the other day with a laser beam. We have unmanned planes armed with rockets (successfully tested on a car full of people in Yemen recently). We have the most advanced military on the planet and probably some REALLY amazing and scary shit we dont even know about. War is not an easy thing any more... it was in the past.
but of course, when the aliens come or the robots take over,... we may very well be helpless.
.... but they will probably spare the bananas