I recently came across the answers to this question by 10 historians and for some reason, I felt dissatisfied. Most blamed the usual suspects - Serbia, Austria-Hungary, Russia, Germany, France and Britain, or the alliance system, Prussian bellicosity etc.
http://www.bbc.co.uk/news/magazine-26048324
Why is it, that WW 1 is not seen as the inevitable culmination of a system of international politics where might was right, and the nation with the right kind of military and economic power could take over the wealth and the land of another! Once the European countries 'ran out' of weak nations they could subdue and conquer (virtually all the lucrative territories in Asia and Africa were conquered by 1900s), it was inevitable that conflict broke out among the European powers themselves, this time for each others resources!
Without colonies to exploit economically, Germany could have had all the technological, scientific and cultural advances, but it would never be as rich as Britain. With Britain and France already controlling most of the world's wealth, how could Germany get rich without triggering a war? Therefore, it follows that German militarism and shortsighted leadership may have been the proximate cause of WW I, the root cause of WW I was the world political order of colonies and empires, and this European war was simply a culmination of violence unleashed by the European powers first on the Asians and Africans which culminated in war on the European continent.
Why is this view not more mainstream?
This is the first time I am posting in AskHistorians, so I am not sure if I am adhering to the rules and guidelines. Please accept my apologies if I have broken any rules.
A good book to check out is Europe's Last Summer by David Fromkin. He delves into prevailing attitudes about who started the war and why, but then mines the work of historians who, starting in the 1960s began uncovering more useful documents (especially internal government documents among the major players) to sort out exactly what happened in 1914 and why. I thought he made a really compelling argument about the motivations of Austria and Germany in particular, and it definitely left me with a lot of new things to consider about the outbreak of the war. Give it a read.
That is an interesting article, and causing some debate over on /r/wwi, which I am enjoying watching. You may also find some of these Frequently Asked Questions about the start of WWI to be helpful.
One could just as easily argue pretty much the opposite of your hypothesis.
It could be said that European nations were pretty much continually at war with one another until Britain became the hegemonic power after the Napoleonic wars. The 19th century era of colonization was an unprecedented era of peace in Europe (although there were a few wars).
The end of the era of peace and the start of the first world war might be blamed on the failure of colonialism to support the hegemony of Britain. Despite having the largest empire the world had ever seen, and despite being able to run it on the cheap, Germany, with almost no colonial empire at all was able to build an economy which grew faster than Britain's and came to rival it.
Colonialism didn't work. The colonies cost the British Empire more than their benefits. A rival superpower, with an economy based on focusing on industry at home rather than administration abroad, decided to challenge the world order. So, we had WWI.