The great nineteenth-century Prussian general Field Marshal Helmuth von Moltke, ‘The Elder’, once declared that no operations plan survives contact with the enemy. But no one has suggested – least of all Moltke – that an army or a commander contemplating a military operation should have no plan. The same can be said about previous experience of war. A new war is likely to have such a different shape and character from the previous one that previous experience might be found to be of no value or, indeed, even misleading. Army commanders are often accused of preparing for the past war rather than the future one. But no one has suggested that previous wartime experience is not valuable in an army about to embark on a new war.

This chapter explores some of the major strategic questions faced by Callwell as Director of Military Operations, including the German colonies, Salonika and Mesopotamia. It also assesses his views of other important issues with which he was concerned, such as munitions, manpower and the army’s relations with the press. The chapter looks at his time as an ‘odd-job’ man for the War Office (1916-18), during which he was engaged in various interesting (and not unimportant) roles. Finally, it examines his later works, especially his autobiographical and biographical work. Most infamous is his study of Sir Henry Wilson, a highly controversial work.