Double Flash

Norman Dombey · Israel, South Africa and the Bomb

On 22 September 1979 at about 1 a.m. GMT, a US Vela satellite passing over the South Atlantic detected a double flash of light in the vicinity of Prince Edward Island. The satellite had been launched in 1969 in order to detect atmospheric nuclear tests. When a nuclear weapon explodes in the atmosphere, the heat of the fireball strips the electrons off the atoms and molecules of the surrounding air. For a fraction of a second the ionised air is opaque, until the blast blows it away. The resulting double flash is the signature of a nuclear explosion. At the time the Vela had successfully detected 41 such explosions. Guy Barasch of Los Alamos, the laboratory which ran the Vela programme, concluded that ‘naturally occurring signals would not be mistaken for that of a nuclear explosion’ and that

the nuclear signature is orders of magnitude more energetic than any other terrestrial phenomenon that might simulate it… This double flash is a unique feature of a nuclear explosion. And we detected a double flash on September 22.

The CIA report from December 1979 states that ‘on the basis of available information we cannot determine with certainty the nature and origin of the event of 22 September 1979’ but that analysis suggested

an explosion was produced by a nuclear device detonated in the atmosphere near the earth’s surface; it had a yield equivalent to less than 3 kilotons; it took place within a broad area, primarily ocean, that was generally cloudy.

No radioactive debris was detected, but that was consistent with rainy weather.

The incident came at a difficult time for President Carter, who was preoccupied with the Iranian revolution – the US hostages were seized on 4 November 1979 – and was faced shortly afterwards by the Soviet invasion of Afghanistan. Prince Edward Island belongs to South Africa, which was allied with Israel at the time. If the US had determined that either country had exploded a nuclear weapon, it would have been bound under its own laws to cut off aid to that country, so the administration played for time by setting up a panel under Jack Ruina of MIT to consider the evidence. According to the ABC television reporter John Scali,

from the outset the panel was given guidelines to help give the Carter administration cover – they were tasked to investigate whether the detection had been a false alarm including the possibility that it was of natural origin, possibly resulting from the coincidence of two or more natural phenomena.

The panel dutifully reported that ‘at this date there is no persuasive evidence to corroborate the occurrence of a nuclear explosion on September 22.'

In summer 1980 I visited Los Alamos as a consultant. I tried to discuss the Vela findings, but it was soon clear that no one involved with the work was allowed to talk about it. It was also clear that they believed that the double flash was caused by a nuclear explosion.

According to the CIA report,

In September 1979 some special security measures were put into effect which indicate that certain elements of the South African navy were exercising or on alert on 22 September. The harbor and naval base at Simonstown were declared, in a public announcement on 23 August, to be off limits for the period 17-23 September… Also, the Saldanha naval facility, which includes a search-and-rescue unit, was suddenly placed on alert for the period 21-23 September.

In practical terms, the testing of a nuclear device at sea would not have needed more than two or three ships including several dozen crewmen and technicians.

The report considered three principal scenarios: (i) a secret test by South Africa; (ii) a secret test by Israel; and (iii) a secret test by South Africa and Israel. A secret test by South Africa was a possibility; they had already attempted one in 1977. The report, however, found that ‘we have no specific evidence that senior military officers perceive any imminent, or an eventually important, role for nuclear weapons.' A secret test by Israel, either alone or with South Africa, made a lot of sense. While the report is heavily redacted, it states that

the Israelis might have conceivably foreseen needs for more advanced weapons, such as low-yield nuclear weapons that could be used on the battlefield. Or they might have considered desirable a small tactical nuclear warhead for Israel’s short-range Lance surface-to-surface missiles. Israeli strategists might even have been interested in developing the fission trigger for a thermonuclear weapon. If they were to have developed reliable nuclear devices for any of these weapons without access to tested designs, moreover, Israeli nuclear weapons designers would probably have wanted to test prototypes. A low-yield nuclear test conducted clandestinely at sea could have enabled them to make basic measurements of the device’s performance.

The report continues that South African weapons designers would prefer to test their own prototypes ‘unless the Israelis had offered advanced weapon technology’ to South Africa.

Thanks to the research done by Sasha Polakow-Suransky, we now know that is precisely what happened. Israel had offered to supply South Africa with Jericho missiles, including a nuclear warhead. On 25 September 1979 P.W. Botha ‘told a provincial congress of the ruling National Party that “South Africa’s enemies might find out that we have military weapons that they do not know about.”’ Martin Walker reported in the Guardian in October 1980 that Israel’s defence minister Ezer Weizmann made a secret three-day trip to South Africa around that time during which he met the head of South Africa’s Atomic Energy Board. Seymour Hersh, in The Samson Option, quoted Israeli sources who confirmed that it was a joint Israeli-South Africa operation. Commodore Dieter Gerhardt, who was at the time commander of the Simonstown naval base, told the Johannesburg City Press that the double flash was produced by an Israeli-South African test codenamed Operation Phoenix (he may not be a completely reliable witness, having later been convicted of spying for the Soviet Union).

Given that Israeli-South African nuclear collaboration has been established and that South Africa is now considered to be a responsible member of the international community, we can look forward to further revelations.


  • 26 May 2010 at 4:41pm
    semitone says:
    "If the US had determined that either country had exploded a nuclear weapon, it would have been bound under its own laws to cut off aid to that country"

    I didn't know this! Has the law changed, or is the US bound under its own laws to cut off aid to Israel? One can only hope.

  • 26 May 2010 at 5:13pm
    Oliver Rivers says:
    I'm agnostic on the question of whether Israel offered to sell nuclear warheads to South Africa. However, neither the article by Sasha Polakow-Suransky to which you link, nor the report in the Guardian covering the same issue (, offers any hard evidence to that effect. The Guardian's reasoning is in fact circular; the assumption that "three sizes" of warhead must refer to nuclear warheads is only credible if you think nuclear warheads were in fact on the table.

    • 27 May 2010 at 2:07am
      Muhammad Idrees Ahmad says: @ Oliver Rivers
      As a matter of fact Polakow-Suransky offers plenty. It is another thing if not seeing is a political preference.

    • 27 May 2010 at 2:28am
      pinhut says: @ Muhammad Idrees Ahmad
      This quote from that interview is interesting, too.

      "The other thing worth noting is that Constant Viljoen also went to the Occupied Territories in 1977, and he marveled at the Israeli checkpoint system and, quite frankly, was jealous of it. And he wrote in a report to the South African defense minister, "The thoroughness with which Israel conducts this examination is astonishing. At the quickest, it takes individual Arabs that come through there about one-and-a-half hours. When the traffic is heavy, it takes from four to five hours." And this was part of a document admiring Israel’s internal security apparatus."

  • 28 May 2010 at 5:20pm
    ichthyophagous says:
    You might have noted in the article that not only Peres but the former President of South Africa, F. W. De Klerk, has denied any attempted sale of nuclear warheads. See below: