Measurement is not understanding

McNamara Fallacy:

Nonetheless, the United States lost the Vietnam War. How could that have happened?

The US military walked straight into the McNamara Fallacy.

Quantification at War

The McNamara Fallacy is named after Robert McNamara. As U.S. Secretary of Defense from 1961 to 1968, McNamara was responsible for organizing American strategy in the Vietnam War.

As a business executive, McNamara had learned to put a priority on quantitative metrics. Following along with the professional culture of scientific measurement established under Frederick Taylor, McNamara decided that he could win the Vietnam War by quantifying it.

McNamara tracked the progress of the war by focusing on the ratio of enemy fatalities to American fatalities. As long as there were more enemy deaths than American deaths, McNamara concluded that the military was on the path to victory.

What McNamara didn’t keep track of was the narrative of the war, the meaning that it had both within the military forces of each side, but also in the civilian populations of the nations involved. Instead, he applied the business aphrorism that you can’t manage what you can’t measure and treated his metrics as if they were in themselves the definition of success. McNamara insisted that if factors could not be quantified, they were not relevant to the management of the Vietnam War.