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

The Republic of Korea (ROK) army wasn’t expecting the surprise of combat power that North Korean People’s Army (NKPA) released on them.  The NKPA knew the location of the ROK’s deployed forces since it was infiltrated with the line Crossers and Communist agents.  The NKPA struck when the ROK army wasn’t even deployed for battle, which didn’t help when the equipment wasn’t up to maintenance standards to make them combat ready.  The US and ROK wasn’t prepared to be in an offensive position, when some of the American soldiers were absent on pass to Seoul and other towns.  When the ROK was informed about NKPA attacking they were only able to deploy only one of the three regiments of each division to get in battle position.