The US strategic defence policy has undergone dramatic changes in the last two decades, with more recent changes having placed increased demands on members of the reserve components. Rapid and often unexpected call-ups of reserves for operational missions, both domestic and international, required meeting standards for mobilization and deployment. Standards were in place but not necessarily met. Mobilizations pointed to several areas of unpreparedness; at first, obvious areas, such as members being physically unfit, inadequately trained and improperly equipped and less than competent unit leaders; and later, less obvious areas, in particular, emergent personal adjustment problems. During these mobilizations, unique consequences of stressors on individual reservists were evident, including worries about family and civilian job during deployment, adjustments to returning and reintegration, post-deployment post-traumatic stress disorder and related symptoms, and now suicide. Some have explained these findings, though lacking is a broad explanatory framework. Reserve identity is offered as a preliminary concept to interpret reservists' deployment experiences, post-deployment adjustment, and associated mental health needs, providing a basis for preventive intervention strategies.