Sentence:  "Our brave Ottoman soldiers are not easily frightened by noise, owing to their splendid nerves—and this is a <WSD>war of nerves</WSD>, a war in which strong nerves mean victory." 
Meaning of the word marked with <WSD> tags:  Warfare or other physical conflict in which one or more combatting parties use especially demoralizing and frightening tactics to attempt to unnerve their opponents.