It seems that pretty from Bismarck's sacking on Germany's strategic situation deteriorated. 1890 Germany had treaties with Russia, Austria-Hungary and Italy and the other European powers were not really friendly with each other. 1914-1915 it seems most of Europe was eager to join the war against Germany.
Did the Kaiser have a major role in what happened inbetween?
Although the Kaiser did dismiss Bismarck, leading afterwards to the Re-Insurance Treaty with Russia not being renewed, Leo von Kaprivi (Bismarck's successor) had an important role to play in this decision.
With the Naval Laws, Kaiser Wilhelm's support for the construction of a large Navy to support an assertive foreign policy (Weltpolitik) was a key factor. It should be noted in this case that Graf von Tirpitz and von Bulow (the foreign minister) were also had a role to play as well, with Tirpitz being the head of the Navy and von Below being a key actor in foreign policy.
In the end, I would say that the Kaiser did have a major role to play in creating Germany's disadvantageous strategic situation in 1914, but the presence of other key actors around him should be acknowledged.