34. Memorandum From Secretary of Defense Laird to President Nixon1
- Actions Relative to the North Vietnamese Dry Season Offensive
The situation in Southeast Asia has reflected for the past few weeks and continues to reflect a North Vietnamese capability to launch an offensive against friendly forces in South Vietnam. Enemy forces in the western portion of Military Region (MR) 1, in the Central Highlands, and in Cambodia along the Republic of Vietnam border, have been concentrated and are capable of launching major attacks. In addition, there has been a buildup of North Vietnamese air defenses in the North Vietnamese panhandle and in Laos.
- —Employment of Talos antiaircraft missiles from ships in the Gulf of Tonkin against MIGs in NVN up to 20°N.
- —Employment of antiradar missiles, both air and ship launched, against primary GCI radar control sites outside the Hanoi–Haiphong area when MIGs are airborne and indicate hostile intent.
- —A fourth carrier to support Southeast Asia operations arrived on 3 March.
- —Eight B–52s were deployed to Thailand on 7 February and 29 B–52s to Guam on 11 February, providing a 1500 sortie per month capability.
- —Eighteen additional F–4s were deployed to bases in South Vietnam and Thailand on 8 February. Five additional F–105 aircraft equipped to launch antiradiation missiles were deployed to Thailand. Plans to move three additional squadrons of F–4s from Korea to Southeast Asia have been prepared.
- —Authority for higher sortie rates for B–52s and Tacair was passed to field commanders.
- —Authority was granted to strike 130mm guns in the northern DMZ area during the period 16–17 February.
The measures outlined above and the firm RVNAF posture have disrupted the enemy’s offensive plans to an indefinite but considerable degree. To repeat, however, the North Vietnamese retain a major offensive capability in South Vietnam. Their accelerated air defense efforts likewise constitute a continuing threat to our attack aircraft over South Vietnam, Laos, and to our unarmed reconnaissance aircraft over North Vietnam.
In NSDM 149 you indicated the desire to give our field commanders additional freedom of action in dealing with the surface-to-air (SAM) threat. You specified that as soon as the enemy offensive commences, but not prior to March 1, I should authorize—after receiving your final clearance—tactical aircraft strikes against occupied SAM sites and associated equipment in a North Vietnamese area encompassing:
- —19 nautical miles north of the PMDL,
- —19 nautical miles of the NVN/Laotian border,
- —as far north as 19 nautical miles above the Mu Gia Pass.
While the enemy has not been able to launch the predicted major offensive moves in South Vietnam, General Abrams believes the enemy has been trying to get such an effort underway. In a technical sense, he considers the enemy offensive to have commenced. Considering the overall SAM threat, General Abrams, CINCPAC, and the Chairman, Joint Chiefs of Staff, believe exercise of the NSDM 149-indicated authority to be prudent now. SAM installations are mobile and therefore constitute transient targets. Limited duration strikes can, at best, achieve limited benefits. Extensive strikes over an indefinite period involve, in my judgment, even higher risks and costs. I therefore concur in our military commanders’ judgment that selective and limited duration strikes should be authorized now against occupied SAM sites in the lower NVN panhandle.
I should add that standing authorities to deal with the air defense threat from NVN include authority for:
- —Friendly aircraft and SAMs to engage enemy aircraft over NVN, which by their intentions indicate hostile intent against U.S. or allied aircraft operating outside the borders of NVN.
- —Fighter aircraft, including Iron Hand, to strike any SAM/AAA site in NVN below 20°N which fires at or is activated against U.S. or allied aircraft. In conjunction with the impending offensive, additional authorities were granted to permit engagement of MIGs airborne below 18°N and strikes against active GCI radar sites when MIGs are airborne and indicate hostile intent. The latter authority has been exercised on several occasions.
In summary, I believe our extensive air operations are taking a substantial, though indefinite, enemy toll. Our air efforts have probably contributed to the disruption of Hanoi’s offensive timetable. The North [Page 118] Vietnamese air defense capability and tactics constitute a major and growing threat to our air operations. I recommend we continue to exercise the air operating authorities now in existence. I further recommend you authorize up to three (3) twenty-four hour strikes against occupied SAM sites in the L-shaped geographic area of the NVN panhandle outlined in NSDM 149. The twenty-four hour strikes could be taken in continuous sequence, or as separate periods. In any case, the authority would be exercised prior to May 1.
- Source: National Archives, Nixon Presidential Materials, NSC Files, NSC Institutional Files (H-Files), Box H–062, Senior Review Group Meetings, SRG Meeting Vietnam Assessment 1/24/72. Top Secret; Sensitive. See Nixon’s marginal comment in footnote 1, Document 18.↩
- See footnote 2, Document 10.↩
- Document 15.↩