S4: How did the enemy exploit sustainment weaknesses to contribute to the US withdrawal to the Pusan Perimeter?

NKPA was successful in their opening offensive for multiple reasons including surprise, tempo, and poor ROK/US logistics. UN forces were poorly supplied and suffered critical shortages in ammunition, functioning weaponry, medical assets, and vehicular support. The UN (US) maintained a very lean force on the Peninsula with respect to personnel and equipment which when attacked was not ready to fight. While rail and road networks were available, it required FEC to assemble a supply chain from across the Pacific and deliver supplies on the Peninsula with the appropriate vehicles to move it. As such, this wasn’t vastly improved while in the retreat until UNC began massing forces and supplies IVO Pusan. Additionally, UNC’s logistics plan utilized WWII-era war stock and ammunition in need of refurbishment. The WWII ammunition alone had a 60% fail rate in some instances and the refurbished Sherman and Chaffee tanks in early engagements were inferior to NKPA armor. Altogether, the NKPA was able to achieve the initiative in an offensive operation that outpaced the UN’s ability to resource the conflict until the Pusan Perimeter was established.