Airlift is "operations to transport and deliver forces and materiel through the air in support of strategic, operational, or tactical objectives" (AFDD 3–17, Air Mobility Operations). The rapid and flexible options afforded by airlift allow military forces and national leaders the ability to respond and operate in a variety of situations and time frames. The global reach capability of airlift provides the ability to apply US power worldwide by delivering forces to crisis locations. It serves as a US presence that demonstrates resolve and compassion in humanitarian crisis.