When the fighting broke out on June 25, 1950, he was assigned to defend
Seoul as the 1st Infantry Division's commanding officer. He finally
retreated to South Gyeongsang but made an important contribution to the
defense of the Pusan Perimeter, especially to the victory at the village of
Dabudong.
On the move north, his 1st Division under the United States I Corps became
the first to enter Pyongyang on October 19. He was one of the first officers
to realize the Chinese entry into the war. He assumed the defense of
northwestern Korea but was plagued by a larger Chinese army.
In April 1951, Paik was placed in command of the ROK I Corps in charge of
eastern Korea. He soon found the South Korean military insufficiently
trained; they took intensive training while the battle line was fixed. In
July 1951, Paik was elected to represent the ROK military at the Kaesong
Truce Talk but failed to attain results.
In November, Task Force Paik was set up to destroy communist guerrillas on
Jirisan. The campaign was successfully finished in March 1952. In
recognition of the success, he was promoted to Lieutenant General and Task
Force Paik was transformed to the new ROK II Corps. Then he was appointed to
Army Chief of Staff in July 1952. He devoted himself in building up the ROK
army. In January 1953, he was promoted to the rank of general in the ROK
army; which made him the first 4-star general in the ROK Armed Forces.
