Israeli officials are maintaining their silence over reports that the country's intelligence agencies are behind the Stuxnet computer virus that has wreaked havoc on the Iranian nuclear programme.
Analysts are convinced that the complex "worm" virus was a targeted attack that could have only been carried out by a clandestine agency of a country opposed to the Iranian efforts to acquire a bomb. Countries developing such capabilities include the United States, Britain and Israel.
Iranian officials have denied that the virus has damaged computers in the research centre at the Bushehr nuclear reactor and confirmed only that some of the country's "industrial systems" were targeted. But information published recently by the International Atomic Energy Agency seems to indicate that viruses may have significantly set back Iran's uranium enrichment efforts, which are central to achieving weapon capability.
According to the IAEA reports, only about two thirds of the 9,000 centrifuges installed in the enrichment plant at Natanz are working at full capacity. While no official explanation was given for this, many analysts concluded until now that Western intelligence services had managed to supply Iran with faulty equipment.
Following the spread of the Stuxnet virus and an analysis of its code, it seems that it was programmed to target the computers regulating the Natanz centrifuges. In addition, the Iranian government announced last week that the Bushehr reactor would be activated four months behind schedule.
While both the American and Israeli armed forces are preparing contingency plans for a military strike against the Iranian nuclear installations, many senior defence chiefs in both countries still believe that the most effective path against the Iranians right now is clandestine warfare. Mysterious disappearances and deaths of Iranian scientists and officials and accidents at some of the nuclear centres have all been ascribed to these efforts. The Stuxnet attack fits in with this pattern.
While no country will officially own up to a cyber attack, it is significant that most of the countries currently opposing Iran's efforts, including the US, Britain and Israel, have invested heavily over the last couple of years in developing both offensive and defensive cyber warfare capabilities.
Some analysts have conjectured that a file in the Stuxnet virus code named "myrtus" is an allusion by Israeli programmers to the biblical Queen Esther, who saved the Jewish people from a genocidal Persian, as her real name, Hadassah, means Myrtle. But other experts are doubtful that any country involved in a cyber attack would leave a calling-card.
"Cyber warfare can be waged not only by governments," says an Israeli security official. "Any clever hacker with a computer can do it. But when you combine the technological capabilities with the resources of an intelligence service that can obtain code-words or plant a file or a memory stick in a crucial computer somewhere, the possibilities for sabotage are endless."
Major General Amos Yadlin, head of the IDF's Intelligence Branch, has termed cyber warfare "the fourth dimension of war". In a lecture last year, at the Institute for National Security Studies in Tel Aviv University, Maj Gen Yadlin said, "the twentieth century saw the development of the third dimension, air power, in addition to the ancient battlefields of land and sea. This century, cyber will be the new battlefield."
Over the last year, the Israeli defence establishment has formalised its cyber efforts. The offensive capabilities are concentrated in the IDF's Unit 8200, the central listening and SIGINT unit (similar to GCHQ in Britain) together with Mossad. A special branch of the General Security Service (Shin Bet) has responsibility for defending vital infrastructure from electronic attacks.