USAF firepower: B-26 Invaders bomb logistics depots in Wonsan, North Korea, 1951.
In January 1951, the PVA and the KPA launched their Third Phase Offensive (aka the â€œChinese Winter Offensiveâ€), repeating night attacksâ€”stealthy infiltration of UN Command fighting positions, from behind the front lines, then a numerically-superior, overwhelming assault to capture it. The tacticâ€™s psychological warfare component was accompanying the attack with disquieting loud trumpets and gongs, played as tactical communication and as mental disorientation of the enemy. UN forces had no defense against this tactic, and soldiersâ€™ resolve became â€œbug-out feverâ€; soldiers â€œbugged-outâ€, often abandoning their weapons, while rapidly retreating south.:117 In the event, the Chinese Winter Offensive overwhelmed the UN Command forces and the PVA and KPA conquered Seoul on 4 January 1951.