McNamara relied on the figures, fetishized them. With his perfectly combed-back hair and his flawlessly knotted tie, McNamara felt he could comprehend what was happening on the ground only by staring at a spreadsheet—at all those orderly rows and columns, calculations and charts, whose mastery seemed to bring him one standard deviation closer to God.
In 1977, two years after the last helicopter lifted off the rooftop of the U.S. embassy in Saigon, a retired Army general, Douglas Kinnard, published a landmark survey called The War Managers that revealed the quagmire of quantification. A mere 2 percent of America’s generals considered the body count a valid way to measure progress. “A fake—totally worthless,” wrote one general in his comments. “Often blatant lies,” wrote another. “They were grossly exaggerated by many units primarily because of the incredible interest shown by people like McNamara,” said a third.
The use, abuse, and misuse of data by the U.S. military during the Vietnam War is a troubling lesson about the limitations of information as the world hurls toward the big-data era. The underlying data can be of poor quality. It can be biased. It can be misanalyzed or used misleadingly. And even more damning, data can fail to capture what it purports to quantify.