Casualties. Casualties—soldiers killed or rendered unable to fight by enemy weapons, disease, or accident—reduce combat strength and sap the morale of those personnel who remain fit for service. The outcomes of battles, campaigns, and even wars have often been determined by the casualties suffered by one side or the other.

Casualties may be classified as either battle or nonbattle. Battle casualties include personnel killed in action, wounded in action, captured, or missing in action; nonbattle casualties include those killed or disabled by disease or accident, as well as those incapacitated by psychiatric illnesses (known variously as shell shock, battle fatigue, or Post‐Traumatic Stress Disorder) induced by the stresses of military service.

Since 1775, weapons have become more lethal, and with increased lethality has come an increase in both the number of casualties and the severity of wounds. Before 1850, about half of all battle casualties were caused by artillery. The introduction of the conoidal bullet in the mid‐nineteenth century greatly increased the range, accuracy, and striking power of small‐arms fire, and in the Civil War rifle fire accounted for most battle casualties. By World War I, better recoil mechanisms (which improved the rapidity and accuracy of fire), the introduction of indirect firing techniques, and advances in high explosives and shell design made artillery once again the most destructive force on the battlefield. More recently, landmines and aerial attack (bombardment, strafing, and napalm) have produced significant casualties. The huge number of weapons systems on the modern battlefield and their more rapid rate of fire has also increased casualties, and chemical, nuclear, and biological weapons pose even greater threats to survival.

Prevailing tactical doctrines and practices significantly influence the proportion of soldiers who become casualties. Until the end of the nineteenth century, the dominant tactical methods involved close‐packed linear formations and frontal assaults, both of which exposed attackers to the full effect of defenders' weapons. Since World War I, the wider dispersion of forces on the battlefield and the increased use of cover and concealment have reduced exposure to enemy fire. On the other hand, modern battles involve continuous combat over extended periods, and thus the number of casualties, particularly those due to fatigue and combat stress, has tended to increase.

The assurance of rapid evacuation and effective treatment of the wounded is a major factor in maintaining military morale and the willingness to endure combat. The speed at which the wounded soldier reaches medical treatment is the key element in his chances of surviving his wounds and avoiding permanent disability. Few soldiers who suffer severe wounds will survive unless they receive adequate medical care within six hours.

The principles of military medical evacuation employed by most modern armies were devised by U.S. Army Maj. Jonathan Letterman during the Civil War. Letterman reorganized the existing system of field hospitals, established an ambulance corps, and laid down the principle that rear echelons should be responsible for sending forward the men and transport to evacuate casualties to medical facilities well behind the battle line. Letterman's system reduced both the confusion attendant to the handling of battle casualties and the time required to get the wounded to definitive medical care.

Refinement of Letterman's system and more rapid means of transport further reduced the time required for evacuation in World Wars I and II, but the helicopter dramatically transformed battlefield evacuation. A few primitive helicopters were used in World War II for evacuating sick and wounded soldiers from remote locations. Such use was expanded during the Korean War, and in Vietnam the medical evacuation helicopter all but replaced ground evacuation. The result was a significant reduction in the time required to get a battle casualty to life‐saving treatment. In Vietnam, for example, the average time required for the evacuation of a casualty by helicopter was only 35 minutes. Consequently, the number of wounded soldiers who died was substantially reduced and the chances of avoiding permanent disability or disfigurement improved considerably.

Major improvements in battlefield evacuation since 1860 have been accompanied by equally striking advances in diagnostic techniques, surgery, drugs, and preventive medicine. Before the Civil War, some advances were made in surgical techniques, the use of anesthetics (chloroform), and camp sanitation. However, the half century between the Civil War and World War I saw astounding progress in medical science. Louis Pasteur's germ theory, Jacob Lister's concept of antisepsis, and Wilhelm Roentgen's X‐ray process enabled major steps forward. Surgical techniques improved greatly, and the use of more effective anesthetics became general, as did more potent painkillers such as morphine. Inoculation against infectious diseases, particularly those (typhoid, for example) that severely threatened massed military forces operating under poor sanitary conditions, also became routine.

American military physicians made major contributions to the advance of medical science in the late nineteenth and early twentieth century. Antiseptic surgery was practiced in U.S. Army hospitals as early as 1883, well before Lister's theories were generally accepted. George Miller Sternberg, army surgeon general in 1893–1902, was a recognized pioneer in the field of bacteriology and promoted the work of other military physicians who sought the causes of communicable diseases such as cholera, typhoid, and typhus. Under Sternberg's patronage, Maj. Walter Reed identified the mosquito as the vector for yellow fever, and the subsequent efforts of Col. William C. Gorgas to control malaria and yellow fever made possible the construction of the Panama Canal and the reduction of those diseases worldwide.

The frightful casualties resulting from more destructive weapons in World War I spurred the development of improved surgical techniques and better management of infection. Further advances significantly reduced mortality in World War II and set the pace for even greater progress in medical science after 1945. Effective new drugs, such as sulfa and penicillin, were introduced; X‐ray techniques and equipment were improved; and the use of blood plasma to prevent shock and replace blood volume saved thousands of lives, military and civilian. The global deployment of American forces also prompted research into the causes, prevention, and treatment of a variety of diseases until then little known or understood. Malaria and other endemic diseases were eradicated in certain areas as part of the American military public health efforts.

Medical science has continued to advance since 1945, and the resources now available to the military physician far surpass anything available in World War II. The surgical laser, greatly improved diagnostic technology, and modern antibiotics make diagnosis and treatment more efficient and effective. Recent advances in bioelectronic and biomechanical devices have also substantially improved the chances of restoring to wounded soldiers the nearly full use of damaged limbs and organs.

The rate of death from wounds has fallen significantly in the last 150 years. In the Mexican War (1846–48), 14.9 percent of all battle casualties died from their wounds. The rate fell slightly—to 14.1 percent—in the Civil War, and then declined sharply to only 6.7 percent in the Spanish‐American War. Mortality rose to 8.1 percent in World War I (exclusive of gas casualties), due to the greater destructiveness of modern weapons, but subsequently fell even more sharply. The rate of deaths from wounds after reaching medical treatment was 4.5 percent in World War II and 2.4 percent in Korea. In the Vietnam War, 97.5 percent of the wounded survived, and 80 percent of those later returned to duty.

Until well into the twentieth century, disease, rather than the effects of enemy weapons, was the single most important producer of casualties. In the Revolutionary War, 90 out of every 100 deaths were due to disease. As late as 1865, more soldiers died from disease, shock, or secondary infection of wounds than died from the direct effects of weapons. Even in Vietnam, 75 percent of all hospital admissions were for the treatment of disease rather than wounds. However, the effect of progress in preventive medicine and the treatment of disease on the survival rates of sick and wounded soldiers was profound. In the Mexican War, the rate of death from disease was 103.9 per 1,000 men. The rate fell to 71.4 per 1,000 in the Civil War and then to 34.0 per 1,000 in the Spanish‐American War. In World War I, the rate was only 16.5 per 1,000, and in World War II it fell to just 0.6 per 1,000.

Although the weapons of war continue to grow more destructive, improved tactical doctrine, more efficient evacuation, and advances in medical technology and techniques promise continued reduction in the number of casualties and continued increase in the rate of survival for the sick and wounded. Today, military personnel are healthier and less likely to die from their wounds or from disease than ever before.
[See also Combat Trauma; Medical Practice and the Military.]

Bibliography

Albert G. Love,, Eugene L. Hamilton,, and and Ida Levin Hellman , Tabulating Equipment and Army Medical Statistics, 1958.
Rose C. Engleman, ed., A Decade of Progress: The United States Army Medical Department, 1959–1969, 1971.
Mary C. Gillett , The Army Medical Department, 1775–1818, 1981.
Albert E. Cowdrey , The Medic's War, 1987.
Trevor N. Dupuy , Attrition: Personnel Casualties, in Trevor N. Dupuy, et al., International Military and Defense Encyclopedia, Vol. 1, 1993.
N. T. P. Murphy , Casualties: Evacuation and Treatment, in Trevor N. Dupuy, et al., International Military and Defense Encyclopedia, Vol. 2, 1993.
U.S. Department of Defense , Service and Casualties in Major Wars and Conflicts (as of Sept. 30, 1993), Defense 94—Almanac, Issue 5 (September–October 1994).

Charles R. Shrader