concentrated immediately in the rear of the Kaesong-Sangnyong sector of the 1st US Corps front.
By 25 April, the enemy had launched heavy counterattacks along the entire front from the Hwachon Reservoir west to Munsan-ni in a large-scale offensive effort. However, with two exceptions, the terrain he acquired was given up voluntarily by UN units in orderly planned withdrawals. Of these two exceptions, the most significant was the penetration about 12 miles deep along the 1st and 9th US Corps boundary in the zone of the 6th ROK Division, the other was the bridgehead gained by the enemy south of the Imjin River between the 1st ROK Division and the 29th BC [British International?] Brigade. These two successes, while not decisive, were considered particularly significant since each occurred on a front behind which the enemy had massed a major concentration. The strong build-up of enemy forces in the Kumhwa-Pyonggang triangle had been recognised.
Strong over-all enemy pressure indicated that the first impulse of the "Fifth Phase Offensive" had been initiated. The major effort being in the western sector, where the enemy had massed the 3[r]d, elements of the 18th, and the 19th CCF Army Groups. A strong secondary effort was launched in the zone of the 6th ROK Division where enemy action suggested as the initial objective, the severance of the Seoul-Chunchon route. On the east flank, continued aggressiveness by elements of the 2nd and 5th NK Corps in the Yanggu-Inje area was indicative of an enemy supporting effort initially aimed at the seizure of this area probably to be followed by principal efforts toward Chunchon and/or Hongchon with secondary efforts toward Pyongchang and Yongwol.
Accompanied by a build-up of reserves on the western front, attacking Communists threatened Seoul during the 5th day of their offensive. UN withdrawals and stubborn resistance all but eliminated danger from the former Kapyong salient and successfully contained enemy efforts to exploit their initial gains in the Inje area.
As of 28 April, timely, well-executed UN withdrawals forestalled Communist efforts to accomplish their drive toward Seoul. There was renewed enemy pressure against the ROK bridgehead in North Korea on the east flank.
Although the intensity of the enemy attack had abated slightly as of 29 April, he maintained the capability of assaults in strength along the western sector. This decrease in enemy pressure was perhaps due mainly to logistical difficulties encountered as a result of the deep UN withdrawals along the fronts of the 1st and 9th US Corps, rather than to a CCF tactical decision to limit their offensive effort. (Map 10)
As of 1 May, the quiescent attitude of the enemy, in the west central sector during the previous 48 hours, could hardly be constructed as one of having spent his offensive effort. On the contrary, all available information pointed to preparations for the early resumption of aggressive offensive operations. Deep UN withdrawals on the 1st and 9th US Corps fronts had resulted in breaks in contact and had forced the enemy to take time to probe and displace troops and material forward before he could initiate the second impulse of his offensive. The unprecedentedly heavy southbound vehicle sightings in forward areas during the period 29 April strongly indicated that such operations were being carried out.
Thus far the enemy had committed approximately 50 per cent of the forces immediately available for such employment. With a reserve potential of 14/15 divisions poised in the west-central sector, the enemy was considered to be fully capable of launching at least one more powerful thrust.