Following the capture of Taejon on 20 July, the Red Korean columns of invasion speeded up their “end run” around the Eighth Army’s open left flank. Driving eastward as well as southward, the enemy made such progress during the next ten days that on 31 July the UN forces were pushed back into a chain of defensive positions in southeast Korea. This was the Pusan Perimeter, which must be held if the vital line of communications from the supply port to Taegu was to be maintained.
The Marines jumped off east of Masan on 7 August with the Army 5th RCT and elements of the 25th Infantry Division in the first sustained counterattack mounted by UN forces. General Craig had control of Army as well as Marine units during the most critical period of the initial two days, and carrier-based MAG-33 squadrons provided tactical air support. Enemy resistance was so shattered by the 9th that the Red Korean machine of invasion went into reverse for the first time.
NKPA GAINS
30 JUNE-1 AUGUST
1950
From the 9th to the 13th, when they were relieved, parallel columns of Army and Marine assault troops drove from Chindong-ni nearly to Chinju, a distance of about 40 miles by the seacoast route. It was only a local setback for the enemy, to be sure, but it had a heartening effect for tired UN forces which had known only delaying actions so far.
It also added to the problems of staff officers at Camp Pendleton and Pearl Harbor, since replacements must be sent to the Brigade. With this in mind, the Commandant had begun the organization of the 1st Replacement Draft of approximately 800 men on the date of Brigade activation. These troops, however, were absorbed into the 1st Marine Division when it expanded to war strength, as was a second draft (also designated the 1st Replacement Draft) of 3,000 men.[50]
[50] PacFlt Interim Rpt No. 1, XV:Zebra, 8–9.
On 3 August the 1st Marine Division was directed by FMFPac to send 10 officers and 290 enlisted men to the Brigade by airlift. This draft was to be ready to move from Camp Pendleton by MATS planes on 9 August, but not until five days later did it finally proceed to San Francisco by rail and fly to Japan.
On the 23d another draft of 10 officers and 300 enlisted men from Marine posts in Hawaii and Guam was sent by air to Japan, these troops being replaced by the same number of noncombat-ready Marines airlifted from Camp Pendleton. This process was twice repeated early in September, when two more drafts totaling 20 officers and 590 men flew to Japan to provide replacements and third companies for the 5th Marines of the Brigade.[51]
[51] Ibid.; Col A. L. Bowser ltr to CMC, 11 Feb 55.