Historians writing about the origins of World War I have differed over the relative emphasis they place upon the factors involved. Changes in historical arguments over time are in part related to the delayed availability of classified historical archives. The deepest distinction among historians remains between those who focus on the actions of Germany and Austria-Hungary as key and those who focus on a wider group of actors. Meanwhile some historians, such as Fischer, maintain that Germany deliberately sought war while others do not. The main distinction among the latter is between those who believe that a war between the "Great Powers" was ultimately unplanned but still caused principally by Germany and Austria-Hungary taking risks, and those who believe that either all or some of the ot