[5] On 3 December 1913 Weber was selected to participate in the newly inaugurated German Military Mission (Militärmission) to the Ottoman Empire, headed by Liman von Sanders.

As a specialist in fortifications, when the Ottoman Empire began preparing to enter World War I, Weber was assigned to strengthen the coastal defences of the Dardanelles.

[8] On 5 May Weber was appointed commander of South Group, on the southern part of the Gallipoli peninsula, during a phase of heavy fighting in this sector.

Following criticism of his performance, however, Weber quarreled with Liman von Sanders and was relieved of this command on 8 July.

Formally reinstated in the German Imperial Army, from 22 October to 16 November 1915 he served on the Western Front as commanding officer of 100th Infantry Brigade.