The US homeland is the physical region thatincludes the continental United States, Alaska,Hawaii, US territories, and surrounding territorialwaters and airspace. The homeland is a functioningtheater of operations, and the Department ofDefense (DOD) regularly performs a wide range ofdefense operations within the theater. DOD isresponsible for the homeland defense (HD) mission, and leads the response with support frominternational partners and United StatesGovernment (USG) departments and agencies.The homeland operational environments requirepre-event and ongoing coordination withinteragency and multinational partners to integratecapabilities and facilitate unified action. DODplans and prepares to operate in concert with otherUSG entities.HD, defense support to civil authorities (DSCA),and homeland security (HS) operations or eventsmay occur simultaneously. The Department ofHomeland Security is the lead federal agency forHS. HS is a concerted national effort to preventterrorist attacks within the US; reduce domesticvulnerability to terrorism, major disasters, and other emergencies; and minimize the damage and recover from attacks, major disasters, and otheremergencies that occur. DSCA is support provided by US federal military forces, DOD civilians, DOD contract personnel, DOD component assets, and National Guard (NG) forces in response to requests for assistance from civil authorities for domestic emergencies, law enforcement (LE) support, and other domestic activities, or from qualifying entities for special events.