WW1 started (among other things) because the "superpowers" in Europe had been arming each other for quite a while in fear of aggression from the other superpowers (not completely unreasonable, given the wars of the previous century). This, in turn, forced the other superpowers to invest more in armaments and army. To top it off, they made treaties of alliance/military intervention (the Triple Alliance and the Triple Entente).
The assassination of the archduke was like flipping a light switch in a house saturated with gas. Austria declares war to Serbia, which is defended by Russia, so Germany has to declare war to Russia; Germany expects France to join Russia so they declare war to France, but their battle plans to conquer France require passing through Belgium. The UK needs Belgium to remain neutral, so they declare war to Germany... and so on. Once the wheels are in motion, and everyone is ready for war, war just happens - whether coke is there or not.
That is the canonical schoolbook explanation of ww1, but I don't like how it frames the war as almost inevitable. Notably the Austro-German alliance was only fully formalized during the July Crisis when Germany offered unconditional support for Austrian war ambitions. While Austria and Germany were part of Triple Alliance, it alone would have not made German entry to war inevitable, as evidenced by Italy (the third member of Triple Alliance).
With Germany having major role in both modern drug history (e.g. Merck with morphine and cocaine, Bayer with Heroin) and their decisive role in the beginning of WW1, I think it is legitimate to ask if substance abuse had role in the hawkishness of German leadership.
Quick Google indicates that there is no strong evidence for Wilhem II themselves using significant amount of drugs, but less is known about the other high officials and generals.
Kinda like today. Europe is rearming in response to perceived risks from Russia. Then the “when you have a hammer…” effect: once capabilities exist, actors start seeing situations where using them seems rational—procurement begets posture, posture begets use-cases.
Yeah but if they'd been smoking weed they would have said yeah whatever - I'll have a look at it tomorrow, when Franz Ferdinand got assassinated.