Foreign Relations of the United States, 1964–1968, Volume XXVII, Mainland Southeast Asia; Regional Affairs

261. Telegram From the Commander in Chief, Pacific (McCain) to the Chairman of the Joint Chiefs of Staff (Wheeler)¹

Honolulu, December 18, 1968, 0415Z.

180415Z. Co-relation among South Vietnam, Cambodia and Laos (U).

1. I am increasingly convinced of the fundamental importance of viewing Laos and Cambodia as integral parts of the overall problem of containing Communist aggression in Southeast Asia. Although each is related in its own way to the Vietnam war, the countries of the former French Indochina area are co-related, and need to be treated as a strategic entity. This is certainly how the enemy has always viewed the region.

2. The North Vietnamese design for eventual domination of the Indochina area has been set back by our actions. But the design remains. Our enemy essentially is the old Indochinese Communist Party which is Asian and international—not single-state nationalist—in character. North Vietnamʼs leaders are nationalistic Communists seeking to extend control over all Vietnam. They are also Asian Communists with an ideological stake in Pekingʼs political expansionism. North Vietnam militarily, politically, economically and socially has overshadowed the other Indochinese countries, and is a nationalistic model. Hanoiʼs evident ultimate aim is to bring about and to dominate a viable Indochinese socialist system on its own terms, a sphere of Vietnamese Communist control existing in the shadow of, but relatively independent of, militant Chinese communism. A Communist takeover in South Vietnam, the “test-case”, is a vital step.

3. For Hanoi, the main strategic value of Laos has been as a corridor area. However, the latest enemy offensive actions at Ban Tha Teng and pressures at Saravane and Attopeu highlight the North Vietnamese design on all of Indochina, along with Chinese Communist intentions regarding Thailand. The enemyʼs new aggressiveness in southern Laos further emphasizes that Laos represents two geographic fingers, one reaching south to Cambodia flanking northern South Vietnam, and the other pressing against northern Thailand. Since 1965, the enemy has significantly improved the road network through the Lao Panhandle to meet the mounting logistic requirements of forces in SVN. ChiCom road construction in the northwestern area is continuing, tying together the enemy logistic system in this region. As allied air efforts increase the pressure on the enemyʼs LOC in the Lao Panhandle, more reliance has been placed on Cambodia for transit and storage of supplies in addition to its troop sanctuary utility.

4. The problem of VC/NVA use of Cambodia as a virtual COMZ between Laos and SVN is of constant concern. Sihanouk has been of more value to the Communists as a “neutralist” than as a declared ally; the Communists have been getting all the support they can use plus the bonuses of sanctuary and a secure, natural extension of the Lao LOC. At various times, Sihanouk has both admitted and denied that Cambodia is a VC/NVA sanctuary. He has never admitted, or perhaps has failed to recognize, Cambodiaʼs ultimate role in the Communist design for Indochinese hegemony. Sihanoukʼs tactics and postures swing widely from left to right, as he strives to prevent the war from hurting Cambodia, and to ensure Cambodiaʼs existence as a neutralist nationalist state whatever the future political organization of Southeast Asia.

5. Since the beginning of the insurgency in SVN, the enemy has used the Lao corridor, and subsequently Cambodia, for the movement and storage of supplies, and for force movement and buildup. The Communists have never regarded borders in the area as militarily restrictive. They have crossed them at will in covert movements to and from the battlefield. The highest enemy military and political authority in SVN, COSVN, was located by design in Tay Ninh Province, close to the Cambodian border, permitting quick withdrawals to sanctuary. The B–3 front and elements in the Ashau Valley are similar cases. Enemy forces in their offensive operations usually plan for withdrawal into Laos and Cambodia. Such movements often make the difference between a heavy loss to or the salvation of the enemy force. There are numerous confirmed intelligence reports that main force units were staged from Cambodia for the attacks against Saigon during the 1968 Tet offensive. In recent weeks, large formations of enemy forces have withdrawn from SVN into Cambodia and Laos, to await further developments, replenish their losses and prepare for further action when necessary.

6. Actions to close off this Cambodian supply source, if successful, would bring about increasing and possibly unbearable pressures on the enemyʼs existing Lao LOC and in fact his entire logistic support system. The “Geneva Line” de facto boundary in Laos probably would be violated to a larger extent than it is now by the North Vietnamese in an attempt to provide alternate infiltration routes. Offensive operations by free world military forces on a hot pursuit basis against enemy border-area strongholds which violated Cambodiaʼs border could be executed to cause some adverse international repercussions. But in light of the present favorable political/military situation obtaining in SVN, and if such operations were executed in pursuit, such repercussions might in fact be minimal. There could be some deterioration of the U.S.-Lao and U.S.-Thai relations and loss of covert operational arrangements, if the Pathet Lao/NVN breached the so-called “Geneva Line” thus causing apprehension in Vietnam and Bangkok. Increased Chinese and Soviet political pressures upon the RLG could be expected also. NVA military reaction in the form of “safety-valve” diversionary efforts in Laos would most probably occur. In Cambodia itself, Sihanouk could be expected to fulminate oratorically. But it is questionable he would assess the situation as a widening of the war to Cambodian territory to an extent that would jeopardize his own fundamental policy objectives. There are indications that he might in fact be relieved to see the NVA/VC ejected from his territory and a strong U.S. presence remain in SEA.

7. In sum, events in any of the Indochina countries have an impact or bearing on what transpires in any of the others. All actions, be they military or political, toward resolution of the Vietnam conflict have regional implications. In extension of the single entity concept, and to enhance our current military successes in South Vietnam—I believe we should apply maximum military pressure against the enemy wherever and whenever tactically feasible, including Cambodian border areas, with a view towards causing the greatest impact possible on the Communist overall strategic plans for the Indo-Chinese area. This of course is subject to political considerations.

8. Very respectfully and warm regards.

1. Source: Johnson Library, National Security File, Country File, Vietnam, 5 (D) 1, Allies Troop Commitments, 3/67–1/69. Top Secret; Eyes Only. On December 19, Wheeler repeated this telegram to Rostow, Rusk, and Helms.