In May the enemy became bolder, increasing his probing attacks and patrols, intensifying his artillery fire, and aggressively interrupting U.N. patrols. In May 1952 an estimated total of 102,000 artillery and mortar rounds fell in Eighth Army positions.
As a result of increased Chinese ground action in the 45th Division sector, the division planned an operation to establish eleven patrol bases across its front. Operation COUNTER began on 6 June. By the 7th, ten of the eleven objectives had been taken. The last one (Hi11 191, eight miles west of Ch'orwon) was captured after a 48-hour battle on 14 June. The Chinese immediately launched counterattacks along the entire division front, climaxing their efforts on the night of 28-29 June with an unsuccessful 4-hour attack. The division sustained over 1,000 casualties during the month of June; Chinese losses were estimated at more than 5,000.
Throughout the first half of 1952, the U.N. forces waged a. war of containment. The frontline soldier, meanwhile, hoped that the armistice negotiators would soon reach an agreement.
As the Korean War went into its third year, in June 1952, the deadlock continued. July began with a series of small-scale attacks by both sides. Torrential rains restricted activity in the last week of July and through most of August. For some time the enemy had gradually increased the volume of mortar and artillery fire in support of his attacks, and in September fired a total of 45,000 rounds against the Eighth Army's front.
During the summer of 1952 the air war over Korea intensified. In addition to striking at supply centers, troop concentrations, power plants, factories, and rail and road networks, U.N. aircraft rendered valuable assistance to frontline troops by bombing, or searing with napalm, enemy bunkers, trenches, gun positions, and communications lines. On 29 August the largest U.N. air raid of the Korean War was carried out on P'yongyang, the North Korean capital. During the month of September alone the U.S. Fifth Air Force shot down 64 MIG-15's at a cost of seven Sabrejets.
A series of enemy attacks in October 1952 produced some of the heaviest fighting in more than a year. Most of it centered around two key heights, Hills 281 and 395, northwest of Ch'orwon. The attacks were opened on 6 October with the largest volume of mortar and artillery fire received by the Eighth Army during the war. By 15 October the disputed ground was held firmly by U.N. forces, and the enemy withdrew. Over 2,000 Chinese dead were counted on these two hills after the 10-day battle.