Why wouldn't Willy of neighboring Germany back down?
While he might have thought backing down would turn his foreign expansion efforts to bubbles and damage his moral justification, Willy probably considered the situation from my perspective.
Russia, not even three years after their war, wouldn't want to get involved and would declare non-intervention.
If Russia doesn't intervene, there's no way war would break out.
Conversely, France might have thought:
'Our ally Russia's power is stronger than expected?'
Even though the Russo-Japanese War was between whites and yellows, weren't the war results too overwhelming?
While they'd been in a position of being unilaterally exploited by Russia under the alliance - through loans, technology transfers, bond purchases, agricultural trade openings - wouldn't they want to borrow that alliance's power this time?