To overcome the threats posed by weapons of mass destruction, Navy medicine must take its place in the naval transformation process described in "Sea Power 21." "Sea Power 21" identifies three fundamental concepts that form the foundation of the Navy's continued operational effectiveness: Sea Strike, Sea Shield, and Sea Basing. Navy Medicine has a natural place in the Sea Basing concept—through provision of force health protection from whatever base dictated by the operational commander. But the risk of chemical, biological, and other attack, and their potentially devastating effect on the individual war fighter create a scenario where Navy Medicine must function within the Sea Shield concept as well. Sea Shield extends defensive capabilities to protect the homeland, the joint force, and coalition partners. In the same manner as theater ballistic missile defense, Navy Medicine should act as a protective shield through immunization programs and chemical prophylaxis (prevention of disease with medication), as well as integration of surveillance and detection measures with personal and collective protection. Navy Medicine is a major force enabler in this environment. However, like any traditional weapon system, it is effective only if unholstered and properly employed.