Since World War II, the U.S. military has experimented with special-operations forces, small groups of warriors with the equipment and training to undertake extremely difficult missions. In effect, special forces exist to leverage human capital in unusual tactical situations. Soldiers selected for high physical and mental capabilities, then intensively trained, can theoretically achieve objectives that normal soldiers cannot.
The successes of special operators are well known; they include, most notably, the assassination of Osama bin Laden in Pakistan. But special operations have always faced criticism from more conventionally oriented parts of the military. The basic tradeoff involves the loss of human capital that regular line units suffer when their best soldiers and officers join special-forces formations. Training resources dedicated to special operators may also, in some cases, shortchange conventional forces.