As a species, human beings have always been distressingly assiduous in devising ways to kill each other. Until recently, however, their best efforts have not equaled the random operations of disease. Disease has seldom been thought of as part of the human arsenal of destruction, probably because it once lay beyond effective human control and may still. But in most of the wars in modern memory it has been a bigger killer than battle. There is no obvious connection between the two, but the mere assemblage of men for fighting has generally been more deadly than the weapons they deploy.
The statistics alone are appalling, as a few examples will attest. In the War of the Austrian Succession, 1740–1748, four thousand Americans participated under British direction in the siege of Cartagena. Though there were few pitched battles, only three hundred survived. The historian of the British army, after narrating the military operations at length, concluded that this phase of the war came to an end through “the gradual annihilation of the contending armies by yellow fever.” In the North American theater of the same war New Englanders sent four thousand men to capture the French fortress of Louisburg on Cape Breton Isle. After arriving at the scene, only about half the troops were fit for action. About one hundred died in the assault on the fortress, but of those left as a garrison 890 died.
In the most spectacular battle of the French and Indian War, 1754–1763, in which both commanders famously died on the Plains of Abraham outside Quebec, the British-American losses were 664, the French 640. The garrison of seven thousand that occupied the city was reduced by typhus, typhoid, dysentery, and scurvy to four thousand effective men in the winter that followed. The comparative toll in modern wars has been lowered by a little. In the First World War the losses to combat and disease in the American Expeditionary Force were about equal, but the war was accompanied by a catastrophic epidemic of flu and pneumonia that killed a total of 675,000 Americans, civilian and military, in the ten months from September 1, 1918, to June 30, 1919. This was more than the total battle deaths in the United States armed forces in the First and Second World Wars, the Korean War, and Vietnam combined. Worldwide the pandemic killed somewhere between 20 and 40 million people. In the Second World War the official figures of the Army Medical Corps in the South and Southwest Pacific for 1942 and 1943 show 9,698 men hospitalized for wounds and 539,866 for disease.
The numbers could be multiplied for other places and other centuries, but they do not figure largely in military histories, or in historical assessments of the contests in which they occurred. Elizabeth A. Fenn’s book on the smallpox epidemic that accompanied the American War for Independence is a brilliant exception. Smallpox, along with anthrax and a host of other …