Operation "Chromite", the Inchon Landing was underway. The small two story white concrete building on a former Japanese Imperial Army Base in Northern Tokyo was ablaze in lights at four o'clock in the morning, with intelligence officers anxiously awaiting any enemy reaction to the Allied attack. There were many rumors going around; Five allied destroyers were sunk in Inchon's "Flying Fish" channel or that the North Koreans were unleashing over 200 aircraft they had hidden in caves. None of this happened.

I went through the age-old ritual of spreading books and papers about the desk to look busy. There were no new codes to break. The North Korean Peoples Army (NKPA) had maintained an ominous and troubling radio silence for two days. I went to my triple-locked file cabinet and dug out some Soviet Air Force traffic that I had been working on recently and proceeded to study it.

After a while, Lt. Toft returned with some canary yellow intercepts and came over to my desk. "These just came in, it's a new network, we haven't heard it before" she said as she laid them on my desk. I looked at several pages of four digit groups that looked vaguely familiar. I said "Thank you" as she looked over my shoulder for a moment then returned to her desk.

It was a syllabic substitution system similar to one I had broken two months ago - the pre-war NKPA traffic. It took about a half-hour to reduce the specific key. I turned and asked Lt. Toft "Who is translating this morning? This stuff is just about ready". She left the room and returned with Captain Youn P. Kim, who pulled up a chair and sat down next to me.

The Pyongyang-born WWII veteran Captain and myself had a developed a close relationship in the past two months. There was no military formality. We frequently, on a day-to-day basis, consulted with each other on Korean terminology or cryptographic nuances. Although he lacked the academic credentials of some of his civilian colleague translators, he had an uncanny military knack of winnowing out the most important military messages. He was without a doubt the most prolific and valuable translator.

I pointed to the first message and said "I'm not sure about this number, it's either a 6 or 7. Evidently, the message is from the 26th or 27th some-kind-of Brigade, what do you make of it?" The Captain looked-up at me, startled. "It is the Inchon situation report from a unit of the 27th coastal-defense brigade. The marines have taken Wolmi-do Island in Inchon harbor". I made several corrections to the Korean text as he looked on and made a few suggestions. He then said "I'll take this one, get the rest to me as fast as you can".

The first message was translated and flashed to General MacArthur on board the command ship Mt. McKinley, off the West Coast of Korea. It was reported that the General was pleased. Subsequent messages in this system indicated that the 27th Coastal Defense Brigade was headquartered in the Munsan area. It directed units of the 17th and 18th Divisions, deployed west of Han River, to counter-attack the Inchon beachhead. Two columns of six Russian T-34 tanks each, accompanied by infantry, were ordered to ambush the advancing first marine division at two specific locations.

On September 16th, the first column was found three miles east of Inchon and attacked by two flights of "Corsair" aircraft from the aircraft carrier Sicily. One American plane was shot down killing the marine pilot. A follow-up assault by combined infantry and "Pershing" tanks completed the destruction of the column. In the early morning of the 17th the 5th Marines set up an ambush of their own and annihilated the second column killing over 200 North Koreans. The Inchon landing was secured.

In early October Captain Kim, Lieutenant Chun and PFC Dick Copeland were dispatched to Korea to link up with the 60th Signal Service Company to set up an ASAPAC advanced decoding and translation unit. Kim had an opportunity to view the destroyed Russian T-34 tanks and reported back the scene to us in Tokyo.

Several days later the U. S. Marines reciprocated the Army's intelligence contribution to their efforts. The first hard-copy confirmation of our code-breaking efforts arrived. The NKPA codebook had been captured, supposedly by the marines as they overran the 18th NKPA Division's command post. Major Swears came into the office looking for me. I was downstairs in the latrine, so codebook in hand, he encountered me as I was zipping up and walking away from a urinal. "The marines picked this up this morning" he said as he handed it to me. It was flown from recently re-taken Kimpo airfield to Tokyo. The big numerals "001" were printed on the cover of a roughly 14 inch by 8 inch thin book. I glanced through it and saw we were right on target as far as our code recoveries were concerned, with only a few synonymous variations. The Major stepped up to a urinal as I replied "Too bad, they stopped using it two days ago, but it will sure confirm a lot of our assumptions, thanks". It was a strange location to discuss one of the significant intelligence coups of the Korean War.

I always wanted to meet up with and buy a drink for the marine or marines responsible for this. They realized the codebook's value, and rather than keep it as a souvenir, which was frequently the case, it was speedily forwarded to the right headquarters.

Some large North Korean units had panicked and were transmitting in plain text again. A new "Defense Command" was established to control the fighting in the West and the defense of Seoul. The "front-line HQ" was directing the NKPA withdrawal in the East. When the lines stabilized the NKPA resumed using the codebook and variations throughout the first year of the war. It proved to be a valuable intelligence asset.


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