“Be modest about what mil­i­tary force can accom­plish and what tech­nology can accom­plish,” Gates said.

He urged his audi­ence to have an “appre­ci­a­tion of limits” of mil­i­tary power, arguing that although the U.S. has achieved huge advances in tar­geting and intel­li­gence that have made attacks more pre­cise, war­fare is “inevitably tragic, inef­fi­cient and uncertain.”

The com­ments amounted to a cri­tique of a mil­i­tary theory called “effects-​​based oper­a­tions,” which argues in part that the gov­ern­ment can care­fully craft mil­i­tary inter­ven­tions to have a pre­dictable impact.

“Look askance at ide­al­ized, tri­umphalist or eth­no­cen­tric notions of future con­flict that aspire to upend the immutable prin­ci­ples of war: where the enemy is killed, but our troops and inno­cent civil­ians are spared,” he said.

The above from Defense Secretary Robert Gates.