295. Memorandum From Stephen Low of the National Security Council Staff to the President’s Assistant for National Security Affairs (Kissinger)1


  • SR–71 overflights of Cuba

In June 1974 the USIB approved an intelligence requirement of overflights of Cuba at the rate of one every three or four months. On August 15, 1974, you approved a request to replace the U–2 overflights of Cuba with SR–71s, but directed that there be a mission every month to six weeks. Before making this shift, we had reduced the frequency of U–2 flights to one every three months. The substitution has now been accomplished and five SR–71 flights have been flown. These flights are different from the U–2 in that the plane is not visible, but a slight noise and pressure impact can be felt from the sweep of the sound barrier. Whether for this reason or other, the Cubans have protested the SR–71 flights by formal note and made token attempts to interfere with the flights. Their tracing of the flights has improved. The only U–2 protests on record date from the 1964 period.

Though the risk of effective interference with these flights by the Cubans is small, the lack of any significant intelligence-gathering need for the flights raises the question of whether we want to continue them at the present level of frequency. The following are pros and cons of reducing the frequency from the present 10 to 12 annual flights, to 4 to 6.


—The primary intelligence needs are served by satellite coverage. There is no intelligence requirement for the flights, though they do provide supplementary data.

—The point has now been made with the Cubans that the SR–71 has been substituted for the U–2. They know that we are maintaining surveillance.

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—Though we believe the flights are virtually impregnable from missile or aircraft attack, the frequency of 10 to 12 flights a year creates a comparatively larger exposure to error or equipment failure.

—Reduction of frequency fits into the climate created by the more conciliatory tone of recent statements by Cuban leaders and gives an indication of a response without the need for public actions or statements.

—Maintaining the flights still provides us with flexibility to make further gestures at a later date.

—The sonic “boomlet,” though slight, provides a target against which Castro may feel a need to react.


—According to our best information, there is no way in which Cuba can interfere with the flights. They are carefully managed so as to abort in case of malfunctioning. Thus, the chance of something going wrong is not great.

—The greater frequency gives us more flexibility in terms of the kind of message we want to send the Cubans.

—The continued high level of flights is an indication to the Cubans that we are not prepared to bargain lightly.

I am personally persuaded by the lack of any significant intelligence need for the flights and the unnecessary exposure to error which this number of flights creates, that there is merit in stretching out the interval between flights to 8 to 10 weeks, which would result in an annual level of 4 to 6 flights.


That you approve a lengthening of the interval between flights from 4 to 6 weeks, to 8 to 10.

This memo has been coordinated with Rob Roy Ratliff.

  1. Summary: Low recommended a decrease in the frequency of U.S. reconnaissance flights over Cuba.

    Source: Ford Library, National Security Adviser, Outside the System Chronological Files, Box 2, 3/2/75–3/10/75. Secret. Marked, “Outside System.” Sent for action. No decision is recorded on the memorandum. In April 22 and July 22 notes to the Department of State, sent through the Embassy of Switzerland in Havana, the Cuban Foreign Ministry protested against April 9 and July 17 violations of Cuban airspace by SR–71 reconnaissance planes. (Both ibid., NSC Latin American Affairs Staff Files, 1974–1977, Country Files, Box 2, Cuba—Political, Military 2)