three regiments that moved directly across the DMZ. After July
 the pace of infiltration slackened somewhat, and it appeared that
 the Communist Regular force structure had reached planned levels.
 Most of the infiltration thereafter was to provide replacements
 in existing units.*
 11. During 1967, however, the introduction of organized units
 resumed -- six regiments thus far -- and the flow of individual
 replacements has continued. This mixture of units and individual
 replacements, plus the special situation along the DMZ, complicates
 an estimate of total infiltration. Not only is there the usual lag
 in identifying new units and infiltration groups, but there is less
 chance of capturing personnel or documents from each of the numerous
 small replacement groups. There is also the problem of the units
 that suffer casualties in the DMZ area and return to North Vietnamese
 territory for replacements;; these latter cannot always be identified
 as new infiltrators when the units return to South Vietnamese
 territory. A similar problem applies to other border areas.
 12. Infiltration thus far in 1967 totals about 35,000 in all
 categories (accepted and possible). Allowing for the probability
 that later information will raise these figures, and extrapolating,
 * The representative of the Assistant Chief of Staff, Intelligence,
 USAF, reserves his position on the penultimate sentence.
 -11-
 
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