10 U.S.C. § 12309: Reserve officers: use of in expansion of armed forces

When an expansion of the active armed forces requires that officers of the reserve components who are not members of units organized to serve as such be ordered as individuals to active duty (other than for training) without their consent, the services of qualified and available reserve officers in all grades shall be used, so far as practicable, according to the needs of the branches, grades, or specialties concerned.