What if Clemenceau wins the January French presidential elections. OTL he loses to Paul Deschanel; the latter was afflicted with mental illness and resigned in Sep 1920. ITTL Deschanels breakdown could occur earlier, giving Clemenceau the presidency.
This could have some interseting developments for the French Army:
Clemenceau's military advisor General Mordacq had proposed a substantial reform of the Conseil Superieur de la Guerre (Army Council) that Clemenceau supported.
Mordacq's CSG had eight generals, four of whom would return to command each year and being replaced from elsewhere within the army and alternately chaired by one of the three Marshals (Foch, Joffre & Petain). OTL the CSG became unwieldy, reactionary and incapable of unity of decision making. By changing the dynamics of the CSG we can pre-solve many of the later problems that confront the French army.
Who knows, maybe France doesn't fall in 1940...
However, what would be the effects for Weimar Germany? or Europe?