A very careful examination of the famous case of the RMS Lusitania, the torpedoing of which in 1915 became an important factor in the eventual American entry into World War I.

Although the book gets off to a slow start – the author devotes over 50 pages to the outbreak of the war – once he gets started, Butler does a masterful job of unraveling the complex issues involved. He provides a thoughtful look at the intricacies of the “cruiser rules,” which had government commerce raiding for generations, and how they were affected by changes in technology and policy.

With regard to the Lusitania herself, Butler demonstrates that the ship was definitely carrying contraband. But he goes on to conclude that despite this the U-20 had no way of knowing that the ship was operating in violation of international law, and that it was thus not a legitimate target; In short, the sinking was a “bad bust.”

Butler then proceeds to delve into the political ramifications of the sinking. The result is a valuable book for anyone interested in the origins of World War I, in the law of war, or in the history of submarine warfare.