The greatest threats to America's public health include accidental importation of deadly diseases by international travelers and the release of biologic weapons by our adversaries. The greatest failure is unpreparedness because international travel and dispersion of biologic agents by our enemies are inevitable. An effective medical defense program is the recommended deterrent against these threats. The United States has a federal response plan in place that includes patient care and patient transport by using the highest level of biologic containment: BSL-4. The DoD has the capability to provide intensive care for victims infected with highly infectious yet unknown biologic agents in an environment that protects the caregiver while allowing scientists to study the characteristics of these new agents and assess the effectiveness of treatment. Army critical care nurses are vital in the biologic medical defense against unidentified infectious diseases, accidental occupational exposures, or intentional dispersion of weaponized biologic agents. Research that carefully advances healthcare using BSL-4 technology addresses the challenges of the human element of BSL-4 containment patient care, and BSL-4 patient transport enhances our nation's ability to address the emerging biologic threats we confront in the future.