WW1 was caused by a series of interlocking peacetime treaties - it was a powder keg waiting to happen, and as it turned out the incident that caused the catastrophe was relatively small.
HOWEVER, the German government under the Kaiser played a VERY significant role in creating that situation of interlocking treaties - as, indeed, France and Britain also played; but the German government was very aggressive in trying to build colonial clout oversees and to form alliances in Europe that could overwhelm the rest of Europe. Even ministers like Bismark who just wanted the unification of Germany and little more than that were taken out of power for not working toward this end.
They were so desperate to be a heavy player in Europe that they neglected the very real human value of what they were doing.
There were no good guys in World War 1 - at least as far as Europe is concerned.