Reaping the Rewards of Co-Operation. Franco-British Intelligence Sharing during the Gas War, 1915-1918

Abstract

Based on British and French archive material, this paper seeks to contribute to the limited “coalition warfare historiography” by exploring a neglected but revealing aspect of Franco-British chemical warfare between 1915-1918: Intelligence sharing. A contextual overview of the two allied intelligence services prior to and following the outbreak of war highlights their complementary strength and global reach. The tactical and strategic significance of French and British intelligence failures at the time of the first German poison gas attacks in April 1915 is examined and contrasted with subsequent allied experience. The discussion focuses upon the two most productive sources of allied intelligence information, mainly reports from secret agents and enemy prisoner of war interview digests. The volume, quality and detail of this material, and its importance to the Franco-British gas war effort are underlined. The article demonstrates how closely and effectively the two allies co-operated by exploiting their shared intelligence data to successfully anticipate German initiatives and to mitigate the searching battlefield challenge posed by an enemy whose technological superiority and resource advantages were evident especially during the earlier periods of the gas war on the Western Front.