This is a brief primer on the legal aspects of military-based, international humanitarian and civic assistance, with an emphasis on UK and US authorities and limitations. Military doctrine and plans need to create consistent, clear and coordinated guidelines reflecting HCA missions competing with other politico-military objectives, done with less money, and fewer assets than in the past. Based on those changing policies and realities, this paper will close by suggesting some guiding principles for why and how US and coalition forces should accomplish HCA, instead of dubious predictions of when and where HCA will take place.