Or the Kaiser could have ordered demobilization, fired any general who refused, told Franz Josef "you're on your own", and released a statement in the international press and on the radio that Germany was "absolutely neutral in the Balkan dispute. Austria-Hungary's fate is its own affair."
In such a case, a friendless and isolated A-H would have agreed to Serbia's acceptance of 9 out of 10 of their demands, and that would have been that.
EDIT: got the number of demands in A-H ultimatum wrong