In 1949, DPRK had four times as many military aircrafts as ROK. Since then, the gap between them had continued to widen. Shortly before the outbreak of the Korean War, DPRK possessed ten times more aircrafts than ROK. Inferiority of ROK air power weakened the power of deterrence against the DPRK's attack, and became a serious obstacle to defending against the attack of mechanized units of DPRK at the beginning of the war.
In this paper, the failure of the air power buildup policy is analyzed by dividing it into three periods. Immediately after taking office, the Rhee government attempted to build an offensive air force, including B-25 bombers, but this policy conflicted with USA policy of containment against USSR. USA sets a criterion that air aid to ROK is limited to 'air liaison detachment' with the size of about 12 aircraft. In the spring of 1949, the Rhee government recognizing the threat of the air power inferiority, proposed a more realistic plan to build a defensive air power to USA and requested aid. However, USA held on the criterion of 'air detachment'. It was not until 1950 that USA began to sympathize with the problem of inferior air power. Korea pursued a policy of reinforcing the military units with new recruit before receiving aircraft. However, the response of USA was too slow, and DPRK went to war before air aid for ROK was implemented.
Although Korea's air power buildup efforts failed, the personnel recruited during this period became the basis for rapid adaptation when receiving aircraft aid after the outbreak of the war. However, the blueprint for air power buildup established at the time became the standard for ROK’s air force buildup policy during the war period.