Defense Health Agency. The Defense Health Agency (DHA) is a joint, integrated Combat Support Agency that enables the U.S Army, U.S Navy, and U.S Air Force medical services to provide a medically ready force and ready medical force to Combatant Commands in both peacetime and wartime.
Definition of preemption. 1a : the right of purchasing before others; especially : one given by the government to the actual settler upon a tract of public landb : the purchase of something under this right.
The at-will presumption is a default rule that can be modified by contract. For example, a contract may provide for a specific term of employment or allow termination for cause only. Typically, U.S. companies negotiate individual employment agreements only with high-level employees.