Office of the Historian

141. Memorandum From the President’s Assistant for National Security Affairs (Kissinger) to President Nixon1

Washington, March 1, 1971.

SUBJECT

  • North Vietnamese Infiltration

Since early January it has not been clear whether Hanoi has continued to send new infiltration groups southward, or whether this activity stopped at that time.

  • —The uncertainty arises because we have not intercepted any more communications from an important enemy way station used by infiltration groups moving through southern North Vietnam.
  • —Prior to January 5, we were able to intercept messages from this station on a regular basis, and these gave us a timely and accurate picture of enemy infiltration.
  • —But we have not heard from this station since January 5. At first, it seemed likely that the station was not reporting because there were no infiltration groups moving. We have since learned, however, that this station shifted to a new location on January 5, and that it may no longer need to use a short wave radio to communicate.
  • —More recently, some infiltration groups have been detected in the Laotian panhandle which almost certainly left North Vietnam sometime after January 5.
[Page 438]

This recent information has removed some of the uncertainty, but it has also raised a fairly serious intelligence problem.

  • —It now seems clear that infiltration from North Vietnam has continued since January 5. We do not yet know the extent of it, but we should have a better idea as other infiltration groups are detected on the Ho Chi Minh Trail.
  • —It is also virtually certain that we have lost our ability to detect infiltration groups moving within North Vietnam. Unless we are able to compensate, our information on infiltration in the future will be much less timely and complete.

I have asked Mr. Helms to conduct a thorough review of our intelligence collection techniques on infiltration and to search for some new exploitable links in the enemy’s infiltration system.

  1. Source: National Archives, Nixon Presidential Materials, NSC Files, Box 84, Vietnam Subject Files, Special Operations File, Vol. VI. Secret; Codeword. Sent for information. A stamped note reads, “The President has seen.”↩