Hostile act

An attack or other use of force against the US, US forces, or other designated persons or property. It also includes force used directly to preclude or impede the mission and/or duties of US forces, including the recovery of US personnel or vital US Government property. (JP 1-02 & JP 3-28).

Source: Terms & Definitions of Interest for DoD Counterintelligence Professionals Office of the National Counterintelligence