At least 70% of Americans between 17 and 24 are ineligible for military service due to obesity, mental health issues, past drug use, criminal records or lack of a high school diploma. Overall, only 13% of young adults express a positive propensity to serve, with women about half as likely as men to consider enlisting. The Defense Department estimates that just 2% out of 20.6 million 17 - 21 year olds have the desired combination of strong academic credentials, adequate physical fitness and an interest in serving. This limited supply compromises national security.