With its highly trained personnel and the ability to move people and material quickly on a large scale, the military can provide significant disaster response assistance.

In the United States, involvement of active-duty military in domestic incidents, including disasters, is known as Defense Support of Civil Authorities (DSCA). DSCA must be authorized by the Secretary of Defense and usually occurs when local, state and non-military federal resources are overwhelmed.

After Hurricane Katrina, the U.S. military agreed to assume a larger role in domestic disaster relief, including taking the lead in major catastrophes like hurricanes. This change resulted from a White House report that concluded that the military and the U.S. Coast Guard proved to be the only federal entities capable of turning the President's orders into prompt action on the ground. Since then, The Partnership for Disaster Response developed an agreement with the U.S. Coast Guard to strengthen port and supply chain security following major disasters.

International military disaster assistance is coordinated in part by the United Nations Office for the Coordination of Humanitarian Affairs. In addition, the North Atlantic Treaty Organization has expanded its disaster response role to include activities outside its members’ borders in certain circumstances.