It is well known that Near-Earth Objects (NEO) and other celestial bodies can be a threat to human existence and civilization. While impacts with large objects occur with very low probability, the consequences can be so catastrophic and irremediable that a program to alleviate this type of threat would seem a very prudent decision. Currently, NASA has been tasked with detecting and characterizing NEOs. However, the role of mitigating these threats is yet to be defined, and may be suitable for USAF responsibility. Mitigation approaches are varied and require further study, but of particular concern are the most difficult scenarios of interception, involving objects with large mass and little advance warning. Although threat mitigation will require important decisions, authorizations, multi-agency coordination and likely international collaboration, some essential long-term planning steps are required to develop and mature key technologies in order to defeat these threats. These steps can be part of an overall long-term strategy for space exploration and utilization that can be part of a global peace-time DOD activity, and that can also greatly increase the welfare of mankind.