Nearly a decade after the United States began to focus its military training and equipment purchases almost exclusively on the wars in Iraq and Afghanistan, U.S. military strategists are quietly shifting gears, saying that large-scale counterinsurgency efforts cost too much and last too long. The domestic economic crisis and the Obama administration's commitment to withdraw from Iraq and begin drawing down in Afghanistan next year are factors in the change. The biggest spur, however, is a growing recognition that large-scale counterinsurgency battles have high casualty rates for troops and civilians, eat up equipment that must be replaced and rarely end...