British trade data and the First World War convoy debate

Prewar British statistical tables reveal the volume and financial value of large two-way flows in food, drink, tobacco, raw materials, and manufactured goods. The figures distinguish necessities such as imported wheat from exports weighted toward alcohol and tobacco. During the First World War, Admirals William S. Sims and John Jellicoe disputed American assumptions that only ships carrying the expeditionary force needed escorts. Independent merchant sailings could not keep the wider supply flow dependable. Convoying therefore organized ordinary cargo ships for mutual protection and escorted passage from origin to destination.