Foreign Relations of the United States, 1977–1980, Volume IV, National Security Policy

194. Memorandum From Secretary of Defense Brown to President Carter¹

Washington, June 13, 1980

SUBJECT

• False Missile Alerts

I think that the following background information is helpful in providing a context for answering questions about the recent false missile alerts.² (U)

Many times each year there are events which result in a display indicating launch of either a single or of a few missiles. These can be caused by a Soviet test launch of ICBMs or SLBMs, which are observed by our infrared satellites. Occasionally they are caused by errors: electronic interference in one of our radars, which results in a false indication; the reflection of sunlight off the top of high clouds or off the surface of a pond which causes a false target in our infrared satellites; communications error; or computer malfunction. (S)

Moreover, there are about 50–60 Soviet test launches every year. Because of the nature of these events (for example, the tracks are generally in a direction that makes them nonthreatening) they are quickly dismissed during a conference of duty officers at NORAD, SAC, ANMCC and NMCC. A few of them, however, may persist long enough or be of such a nature that SAC takes precautionary actions for survival such as alerting crews or starting engines. (S)

In the 1950s and 1960s we had nuclear-armed SAC bombers on airborne alert. Our strategic warning system is good enough today to allow us time to flush our bombers for survivability, so we now keep them on ground alert. A necessary consequence of this mode of operation, however, is that the alert status of the bomber force must be elevated on any missile warning indication, however unlikely the false alert scenario which generated the warning may turn out to be in retrospect. (U)

Against this background, I recommend that we emphasize the following general points in response to questions about the recent false alerts:

• Because of short times of missile flight, a semi-automated warning system is necessary to integrate and display information from multiple sensors, and provide it quickly to the National Command Authorities for decision. (U)

• The automated parts of our warning system may generate ambiguous or misleading indications from time to time. (U)

• Fully recognizing this possibility, the Defense Department has consequently made human safeguards an integral element of the overall warning system. We are confident that these safeguards will catch all false alerts no matter how they are generated. (U)

• False alerts may occasionally result in some precautionary measures for survivability (but the steps taken to date are far short of the airborne alert of bomber aircraft that was continuously in effect 15–20 years ago). (U)

• There is no chance that any irretrievable actions would be taken based on ambiguous computer information. (U)

• The incidents on June 3 and June 6 were caused by errors generated in a NORAD communications device (minicomputer), which resulted in false indications of a missile attack. The minicomputer is used to transmit data from NORAD’s main computer to other command centers. NORAD’s main computer receives warning data from sensors such as satellites and radar, which actually monitor missile launches and flights. The sensors themselves never registered a missile attack, nor did the main computer indicate an attack. Consequently, the false indication was recognized by the appropriate people in the military command centers within 2–3 minutes. (U)

• Our response during both incidents was in accordance with planned procedures. What occurred were the initial precautionary measures to prevent our bombers and command aircraft from being trapped on the ground—measures which do not represent even the beginning of a retaliatory attack. Within the first two minutes, SAC alerted its aircraft crews as a precautionary measure and instructed them to start their engines. This procedure is frequently practiced as part of our training. Nothing irreversible was done in our response to the false warning. (U)

• Although we believe the immediate cause of these incidents has been isolated to a particular device, the Department of Defense has assembled a task force of highly respected computer systems and communications experts to conduct a thorough examination of our NORAD attack warning system. (U)

1. Source: Carter Library, National Security Affairs, Brzezinski Material, Subject File, Box 42, Missile Warning Incidents: 11/79–8/80. Secret. A copy was sent to Muskie. Carter initialed the top of the memorandum.
2. See Documents 190 and 191.