I don't study history but while learning about WWI and the collapse of imperial Russia the Fisher Thesis came up. I didn't think much about it (the premise being that Imperial Germany was ultimately responsible for WWI) until I just recently came across an address by John CG Rohls (he gave it on November 6th, 2014).
I have always assumed, and been taught, WWI was sort of inevitable, and the result of short-sightedness on the party of ALL parties involved. But Rohl's address argued pretty strongly against this and said the Fisher Thesis was the best explanation, and the way he talked about it made it seem like it was the orthodox position to take. Is there a consensus among historians about what caused World War One? Or is this really not considered too important to debate about, and a lot of interpretations are viable.
Firstly, there has never been a true consensus on what caused the First World War as it is an incredibly complex series of both long term events, going back into the late 1800's, and short term events that precipitated in rapid motion with many agenda's of nations and individuals muddying the waters making it very difficult to determine what truly happened in the July days.
In regards to Fischer's thesis, the thesis really hinges on a piece of evidence, a memorandum drafted by Chancellor Bethmann-Hollweg's secretary in September of 1914 which outlined Germany's war aims, hence the title of Fischer's book, 'Germany's Aims in the First World War', or in German 'Griff nach der Weltmacht: Die Kriegzielpolitik des kaiserlichen Deutschland 1914–1918' published in 1961. Fischer argues that the memorandum was far too developed to have been created prior to the outbreak of war and thus its composition must have predated the hostilities in July and ultimately war in August. The conclusion he came to with this is that Germany took the opportunity to go to war before the Russian's were strong enough and thus enact their plans and cement themselves as a world power, 'Weltmacht'. The thesis itself was incredibly controversial at the time, especially among German historians due to the general feeling in Germany at the time to overcome the guilt of WW2 for which the Germans have word for, 'Vergangenheitsbewältigung'. So Fischer essentially laying the entirety of the blame for the Great War at the feet of Germany was an incredibly unpopular move. Fischer's thesis internationally however was never truly accepted as gospel due to the fact that it hinged primarily on the memorandum, which detailed extensive aims, and the interpretation Fischer provided for it which wasn't exactly concrete.
Christopher Clark's 'The Sleepwalkers: How Europe Went to War in 1914' (P:2012) has really put the subject 'to bed' for now at least and the evidence he cites discredits Fischer's thesis to some extent, however Clark had access to much more evidence than Fischer, such as the opening of the archives in Moscow and previously unseen telegrams and letters between what he call 'key actors', diplomats and other such officials of the powers which really sheds light on the complexity of the whole situation. On the last page of his book he wrote the line 'there was no smoking gun', a smoking gun which Fischer claimed he had found. Clark really tries to cover the whole story, particularly paying interest to the irredentist policy in Serbia and their need for war in order to create a pan-Serb nation, of which the succeeded when the formed Yugoslavia. Really what Clark's book demonstrates is the sheer complexity of the whole tragic ordeal and that it is truly difficult to close in on a single point and say that was what caused the cataclysm that was WW1.
Sources:
F.Fischer, Griff nach der Weltmacht: Die Kriegzielpolitik des kaiserlichen Deutschland 1914–1918 (1961)
Christopher Clark, The Sleepwalkers: How Europe Went to War in 1914 (2012)
H.W.Koch, The Origins of the First World War: Great Power Rivalry and German War Aims (1972)
For those, like me, who aren't familiar with the topic but want to learn: Isn't the Fischer thesis more than just "Germany done it", but why they done it (in his view)?