Over the past two decades of conflict, women have served with valor and continue to serve on combat aircraft, naval vessels, and in support of ground combat operations. The expansion of roles for women in the Armed Forces has evolved since the early days of the military when women were restricted by law and policy from serving in certain occupations and units. Women have not been precluded by law from serving in any military unit or occupational specialty since 1993 when Congress repealed the remaining prohibitions on women serving on combatant aircraft and vessels. However, Department of Defense (DOD) policies have prevented women from being assigned to units below brigade level where the unit's primary mission was to engage directly in ground combat. This policy barred women from serving in infantry, artillery, armor, combat engineers, and special operations units of battalion size or smaller. On January 24, 2013, then-Secretary of Defense Leon Panetta rescinded the rule that restricted women from serving in combat units and directed the military departments and services to review their occupational standards and assignment policies and to make recommendations for opening all combat roles to women no later than January 1, 2016. On December 3, 2015, Secretary of Defense Ashton Carter ordered the military to open all combat jobs to women with no exceptions. This most recent policy change followed extensive studies that were completed by the military departments and by the Special Operations Command (SOCOM) on issues such as unit cohesion, women's health, equipment, facilities modifications, propensity to serve, and international experiences with women in combat. These studies also included a review and validation of gender-neutral occupational standards for combat roles where such standards existed. On March 10, 2016, Secretary Carter announced that the Services' and SOCOM's implementation plans for the integration of women into direct ground combat roles were approved. Some concerns about the implementation of the new policy remain, including the recruitment, assignment, and career management of women into the new roles, and the impact of integration on unit readiness. Congress has oversight authority in these matters, and may also consider issues such as equal opportunity, equal responsibility (such as selective service registration), and the overall manpower needs of the military.