It did play a part, of course - but it was not out of the blue, not out of leftfield, not outlandish, as quite a few top German politicians were of the "Reinsurance Treaty = Bad Idea" mindset.
So, Wilhelm simply was halping 😊
The death of the Reinsurance Treaty was to due to causes beyond the monarch(s)'s personalities.
POD is baaad for Russia.
Not that Alexandre was some sort of exceptionaly good monarch, but Nichalas was very sub par ...