American Cryptology During the Korean War [pdf]
foia.cia.gov
foia.cia.gov
Two examples of non-crypto trends cited in the article: The increasing use of VHF by Chinese and North Korean forces, complicating intercept (VHF intercept has to be line of sight) and the near-complete ignorance of traffic analysis and of analysis of Chinese supply management, e.g., that they were ordering large quantities of maps of Korea, etc.
The allies had the data to tell them the Chinese were preparing, e.g., presence of Chinese prisoners captured by ROK forces, but dismissed much of it.
None of the above is cryptology.
We changed the url from http://www.foia.cia.gov/sites/default/files/DOC_0000872751.p..., which has redactions.
The previous URL indicates the article was originally published in Studies in Intelligence, Vol 45 No 3. The CIA has tables of contents for issues from 2002 onwards (https://www.cia.gov/library/center-for-the-study-of-intellig...), which suggest that there is one volume per year and 2002 was volume 46. This is at least consistent with publication in 2001.
Edit: it would be surprising if the 3rd issue of the year was published on the 1st of January. Most likely part of the publication date was entered, and the day and month left at the default value 1.
Edit 2: also, the article refers to being written "fifty years after the outbreak of the war", which would be roughly 1950+50 = 2000.