Britain: Lord Derby’s recruiting report published, 2,675,149 volunteers to date but over 2 million of military age unattested justifies conscription.
Fuller-phone (non-tappable) approved for production and distribution to BEF (10,000 hand-made sets plus c.5000 for US Army 1917-18).
Mesopotamia – First British attempt to relieve Kut: General Aylmer’s 19,000-strong Tigris Corps begins advance astride river, probes Sheikh Saad defences on January 6, but facing overall 30,000 Turkish troops with 83 guns.
Champagne: German trench raids.
Britain: Government answers Germany on Q-ship Baralong affair, offers impartial tribunal if three alleged similar German cases included, Germany contests on January 14.
Austria – CoS Conrad to Count Tisza: ‘There can be no question of destroying the Russian war machine; England cannot be defeated; peace must be made in not too short a space, or we shall be fatally weakened, if not destroyed’.