Calories were made to be counted, but they have generally been counted for two very different reasons. We associate calories with excess, but for most of its history this little unit of energy was linked to shortage. The years since World War II have been a time of cheap and plentiful food, and of obese and sick citizens. Since our own daily struggle is fought against fat, we fail to see that many of the conflicts of the past were wars against hunger. Just as obesity leads to diabetes and human blindness, so plentiful food leads to decadent forms of history and social blindness. We are fortunate to have a bracing book like “The Taste of War,” which does much to correct understanding of the causes of armed conflict and mass murder.

If World War II were only about bad ideas, as we like to think, then we are all safe. Who among us admires Hitler, Himm­ler or Hirohito? But if the war and its atrocities had to do with material want, we cannot so easily separate ourselves from evil. Lizzie Collingham soberly argues that the expansionist designs of both Nazi Germany and imperial Japan must be understood within a world political economy in which the single crucial commodity was food. The British Empire had dominated a global system of free trade that was disrupted by the Great Depression. States like Germany and Japan, unable to supply themselves with sufficient food for their own citizens from domestic sources, had two choices. They could play the game by the British rules, which could seem humiliating and pointless in the 1930s, or they could try to control more territory.

Collingham, the author of “Imperial Bodies” and “Curry,” sketches the hunger motive on the body of the Japanese soldier in Asia, who not only starved others but was starved himself. The energetic Japanese attacks remembered with chagrin by British and American soldiers were driven by the need to capture food from the enemy. In the end, more Japanese soldiers died from starvation and associated diseases than in combat....