As a force projection power, it is critical for the United States to retain the capability to introduce rapidly, credible and sustainable forces into theaters around the world. Maritime prepositioned forces (MPF) are a key component supporting that force projection capability. Currently, there is insufficient strategic airlift to deploy rapidly and sustain heavy U. S. forces as they are currently structured. Operations Desert Shield and Desert Storm validated the value of the MPF concept. The ability to fly in ground forces and integrate them with equipment from pre-positioned shipping greatly enhanced the strategic responsiveness of the Marine Corps and the United States. This facilitated the rapid introduction of a credible ground force into the Persian Gulf Theater of Operations for the United States. The value of this capability was recognized by the United States Army, which has since begun to purchase roll-on, roll-off shipping of its own. America's adversaries, whether they are nation states posing a conventional threat or terrorist organizations presenting an asymmetric threat will not overlook this capability either. As adversaries develop anti-access capabilities, it is critical for the United States to assess continually, the vulnerability of our maritime pre-positioned forces. Forcible entry operations from the sea are a requirement for Marine Corps forces. The Marine Corps continues to rely on MPS as one of the cornerstones of its deployment strategy. However, the Marine Corps is changing the way these operations are conducted. Under the emerging doctrine of Operational Maneuver from the Sea (OMFTS) Marine forces will no longer wait for the arrival of MPF equipment at a port of debarkation and follow the standard reception, staging, onward movement and integration (RSOI) template of Desert Shield and Desert Storm. Several concepts under OMFTS such as Ship To Objective Maneuver (STOM) require the introduction of a Marine Air Ground Task Force with very little organic sustainment directly to the objective. Interdiction of MPF squadrons could significantly degrade U. S. strategic responsiveness or leave Marine Forces stranded in theater without sufficient resources to sustain them. By analyzing threats at the port of embarkation, enroute and port of debarkation for current and future MPF operations a determination can be made as to whether, there is an inherent vulnerability in MPF operations. This analysis concludes that current MPF operations possess vulnerabilities in self-defense capabilities, information access, and organization and loading of the ships. Future MPF operations address the issue of organization and loading however, no decision has been made to provide self-defense capabilities or secure information access. This monograph is significant to the development of both Army and Marine Corps future maritime force projection capabilities. In a chaotic, rapidly changing environment, maritime prepositioned forces provide a combination of responsiveness, sustainability, and forward presence independent of many political considerations such as over flight and land basing. This combination of capabilities makes them an invaluable asset to operational planners and an undeniably high value target to future adversaries.