Palestine – Battle of Jaffa (until December 22): XXI Corps’ 8,100 men and 88 guns surprise cross river Auja on December 21, take 259 PoWs and 5 MGs from 6,200 Turks with 60 guns. 6 Royal Navy ships and 36 Royal Flying Corps planes aid 52nd Division 5-mile coast advance to Arsuf on December 22, Jaffa put out of Turk gun-range. 54th Division captures Bald Hill and two villages inland.
France: Petain Directive urges defence in depth (and on December 22) but not all generals comply.
Flanders: Germans capture fog-shrouded British advanced post west of Messines.
Don: Kornilov arrives at Novocherkask, is made White C-in-C.
Austria: Lower House adopts peace resolution.
Australia: Second referendum again defeats conscription 1,181,747 vs 1,015,159 votes; 1918 recruiting falls to c.2,500 per month.
Russia: Bolshevik Cheka Secret Police founded under Pole Dzerzhinski to ‘fight counter-revolutionaries and saboteurs’.