How did the norm of discrimination become the dominant yardstick to measure the ethics of US airpower? Conventional accounts suggest that as elites and publics embraced norms of discrimination, this pushed US air forces to adopt a precision doctrine, one that demands accurately striking military, and not civilian, targets. Relying on a pragmatic reading of norm contestation and settling, we suggest that conventional explanations have the causal story reversed: it was not the strengthening of the norm of discrimination that led US air forces to commit to precision bombing. It was the commitment to precision bombing that led to the strengthening of the norm of discrimination. As precision technology became available during the interwar period, air-force officers co-opted the language of discrimination to justify their emerging doctrine. This co-optation of the language of discrimination would not only settle these norms as the guiding ethics of airpower. It would also transform them, redefining these norms in ways that privileged the process of precision targeting, rather than the outcome of civilian harm.