Reconnaissance

Aircraft provided reconnaissance: observations of enemy trenches, front lines and weapons helped commanders prepare attacks. However, information did not guarantee that a plan would work. Commanders could receive incomplete or outdated reports, while battlefield conditions could make it difficult for artillery crews to support advancing troops.

Cavalry’s speed remained useful for reconnaissance—finding out where the enemy was—and for harassing enemy forces. However, better rifles and later machine guns made mounted soldiers increasingly vulnerable. A horse and rider advancing towards an enemy could be hit by accurate fire from further away, reducing the effectiveness of traditional mounted attacks.

Herodotus describes a reconnaissance mission to the Indus. Gathering information about a river and its surrounding territory could help a ruler understand routes and plan further action. Reconnaissance and conquest should therefore be distinguished: exploring a region was preparation, whereas bringing it under Persian authority was the political outcome.