EVIDENCE OF CONTINUING VIETNAMESE COMMUNIST WAR PREPARATIONS
DIRECTORATE OF INTELLIGENCE Office of Current Intelligence
TOT!i,if roru wfrgn uatppiai
SC Ho. 6
CENTRAL INTELLIGENCE AGENCY Office of Current Intelligence6
INTELLIGENCE HY. MORA SDL' M
analysis would provide almost conclusive evidence that a sizable unit of North Vietnamese regulars moved into South Vietnam, or along its border, during the lull in US bombings.
5. Theth Infantry Division has for moreear been engaged in forming andnew regimental units specifically for The presence in South Vietnam of threetrained and staffed ln large part byth regulars has already been confirmed by prisoners of war from these regiments. Theyinto South Vietnam in4 and One other regiment infiltrated Innd there are alsoyet unconfirmed--that one additional regiment infiltrated in It has now been some six months since the last unit firmly identified as associated withth Division began -its infiltration to South Vietnam; thus the garrison in North Vietnam would have had sufficient time to have trained several new regiments. It is probably these newly formed units which
now moveo "nam-Cambodia border.
8. It has been estimated that byecember the North Vietnamese had achieved sufficient flexibility In the routing of internal traffic throughout the country to partially ease theproblems that developed during the first few months of tho air strikes. The round-the-clock effort currently under way will allow the North Vietnamese to make an almost completefrom the effects of the strikes. Prior to the cessation of the bombings, the Northwere transporting more supplies into tbe southernmost provinces than were needed for internal requirements. With the increased effort being put forth since the cessation of the air strikes, the level of supplies moved at least to staging depots in southern North Vietnam and Laos has undoubtedly increased markedly.
The North Vietnamese and Chinese are also continuing their efforts to repair the keyroutes between their two countries.
January, anothercommunist military construction unit moved into northwest North Vietnam from Communist China. Aerial photography ofecember disclosedconstruction activity In the vicinity of Ten Bai la an areareviously detected Chinese unit was located. Similar activity has been observed along thoing-hsiang rail, line in northeast North Vietnam where other Chinese engineer units are known to be operating.
North Vietnamese Air Defense Developments
Perhaps the moat dramatic development sinceecember bas been the Increasinglyand effective effort by the North Vietnamese and Chinese Communists against high-altitudeaircraft operating over North Vietnam. During thisotal of five reconnaissance drones have been flown over North Vietnam and Southwest China. All five apparently were shot down either by surface-to-air missiles or by HIG Jetaircraft flown from Chinese or, in one case. North Vietnamese bases.
first drone to be shot downperiod was onecember. Chinesefighters, based at Meng-tzu, penetratednautical miles into North Vietnamesebring down this drone. Anotheranuary, was credited to Jets operating out
of North Vietnam. The third drone lost,anuary, was pursued by Chinese Jets and may have been damaged by them,since it did not return to its recovery area.
increased effectiveness of the-orth Vietnamese airhas resultedonsiderable loss incapabilities. Low-level
has been generally confined to post-strike damage photography and has provided little strategic intelligence. Presumably this Increased aggressiveness vas brought on at least ln partesire by the Communists to conceal military developments being pushed during the stand-dovn ln US air strikes. ThatulldWup Is occurring is borne out by the fact that, sinceecember, eight Sovieteavy transports have been noted flying into North Vietnam. Each of these aircraft is capable of carrying someons of cargo onlight. The nature of the cargo carried by these aircraft is unknown,but the fact that lt is being sent all the way from the Soviet Union by aircraft suggests that it Is priority military equipment, probably related to North Vietnam's air defense system. Prior to the cessation of US air strikes,flights by Soviet heavy transports into North Vietnam had only averaged aboutonth.
13, Also during the lull ln the bombings, Chinese Communist- aircraft have become much bolder in crossing the North Vietnamese border. anuary one flight of an unknown number ofJet fighters, probably based at Meng-tzu, was noted penetrating into North Vietnam aof approximatelyautical miles. Tbe followinganuary, at least one probableased jet Fighter was reflected ln similar activity, this time flying someautical miles into the northeastern portion of North Vietnam.
'the North Vietnamese air force ng advantage of the lull ln US airto Increase training flights. The average number of North Vietnamese Jet sorties during the bombing lull is abouter day, up someer day over previous periods. It is apparent that during the lull ln US air activity, Hanoi is attempting to increase its pilot proficiency ln such areas as regular navigational flying, ground-controlled intercept, and air-to-air
One of the major defects in Northair defense system has long been the lackufficient number of airfields capable of
Jet aircraft. Of the five airfields long enough to be used by jets, only two, Phuc Ten and Sep, have been used as operational Jet bases. During the bombing lull, however, there bas been evidence I
that Jets have,
into and out of two additional fields, Gia Lam near Hanoi and Kien An near Haiphong. In addl-tion,
amese aircraft to Dien Bien Phu airfield. Dien Bien Phu had been out of commission since June5 due to damage inflicted by OS air strikes. Onanuary, at leastorth Vietnameseflew round-trip flights between Gia Lam and Dien Bien Phu, suggesting that the damage has been repaired. Although there is no evidence to confirm it, it is possible that the transport activity into Dien Bien Phu means that it will be expanded to handle jet traffic.
The activation of Klen An airfield for jet fighters and the possible expansion of Dien Bien Phu would considerably increase the range of North Vietnamese Jet fighters. It would alsosubstantially their ability to react to OS air strikes entering North Vietnam both from the coast and from the direction of Laos. All of the air defense activity noted since the cessation of US air strikes suggest that the North Vietnamese intend to make any future air strikes more costly for the US.
Viet Cong Action
rs the cessation of the bombing of North Vietnamno significant changes, and it appears
that the Communist military forces In the South remainombat posture, ready to resume operations at the end of Tet.
TRIN" no '
of tbe Mlchelin area with US troops,earby Special Forces camp in Binh Long Province was attacked by five Viet Cong companies onanuary.