Political map of South & Southwest Asia 21 May 1916 (Russian invasion of Anatolia): With the British evacuating Gallipoli (Gallipoli Campaign) and in trouble at Kut (Siege of Kut), many Ottoman troops could now be sent to the Caucasus front (Caucasus Campaign). Anticipating this, Russia launched a preemptive winter offensive, catching the Ottomans by surprise and capturing the strategic city of Erzurum (Erzurum Offensive). At the same time, the Russians pushed across western Persia (Persian Campaign), temporarily sealing off that region from Ottoman influence.