After the war, Taplett, now a colonel, was assigned as the commanding officer of the navy supply barracks first at Clearview, Utah, and subsequently at Treasure Island in San Francisco Bay and at the Naval Air Station Alameda, California.
When a vastly outnumbering hostile force attacked his Battalion assembly area northwest of Yudam-ni during the pre-dawn hours of 28 November, Lieutenant Colonel Taplett remained steadfast in the midst of heavy fire and bursting grenades as the enemy penetrated to within ten yards of the command post, maintaining communications with and directing the fire of two of his companies which were also under attack and directing the third reserve company in delivering a brilliantly executed counterattack to repel the onslaught in all sectors before daybreak.
Assigned, on 1 December, to break the enemy's main line of resistance which controlled the principal supply route of entrapped Marine units near Yudam-ni, he placed himself in a forward position to observe and control operations and, although he was knocked to the ground by mortar fire on one occasion, and subjected to continuous small-arms and artillery fire throughout two days of intensive action, succeeded in driving the enemy from the area, thereby enabling the FIRST Marine Division to remove all troops, casualties, equipment and supplies in safety.
With the Division train cut in half by hostile fire during the march from Hagaru-ri to Koto-ri on 7 December, and the rear elements unable to advance for a period of more than ten hours, Lieutenant Colonel Taplett moved two miles to the head of the convoy under heavy fire and, effecting a skillful reorganization, started the train moving, at the same time supervising his own Battalion in offensive neutralizing action against the strongpoint.
Promptly calling for air strikes, bringing his own supportive fire to bear and maneuvering two rifle companies into action, he conducted a devastating offensive to annihilate the attackers and enable the Marine units to reach their destination without further opposition.
By his inspiring leadership, forceful combat tactics and gallant fighting spirit maintained against staggering odds, Lieutenant Colonel Taplett contributed to the success of his Battalion in accounting for more than 2,000 of the enemy with a total of only 117 in his own ranks.
Lieutenant Colonel Taplett distinguished himself by conspicuous gallantry in action in the amphibious landing resulting in the capture of Wolmi-Do, Korea, on 15 September 1950 in the Inchon-Seoul operation.
Assigned the mission of seizing and occupying two hills overlooking the regimental objective, Lieutenant Colonel Taplett skillfully carried out this hazardous task and, upon its completion, coolly remained in an exposed area to personally direct the placing of supporting fire on strong enemy positions which were bringing intense small-arms, machine-gun, mortar and artillery fire to bear on the entire battalion front and causing many casualties.
By his inspiring leadership, gallant fighting spirit and courageous devotion to duty in the face of heavy enemy fire, Lieutenant Colonel Taplett contributed materially to the success of the regiment in carrying out its assigned mission and upheld the highest traditions of the United States Naval Service.