Kaspersky, who was introduced as one of the top four experts on cybersecurity in the world, pointed out that cyberweapons “can replicate,” as Stuxnet did — escaping the Iranian centrifuge machinery that was its sole intended target and infecting computers around the globe. Flame is even more complex, monitoring computers it has infected and even recording conversations; it appears to infect computers disguised as a legitimate Microsoft Windows update. The Russian said his concern is the vulnerability of civilian infrastructure that relies on computer operating systems like Microsoft Windows, which cannot be hardened against attack. The only way to secure systems that deliver water, electricity and the economy is through a newly designed OS with security at its core. And until that new system is developed, he said, any country that launches a digital attack is running a terrific risk. “There are a lot of software engineers in Israel, I know,” he said. “But I don’t think there are enough to do it in three or five years.” In the meantime, he said, “I’m afraid that that cyberboomerang may get back to you.”

Silence greeted the warning. Earlier in the day, Israeli Defense Minister Ehud Barak acknowledged for the first time publicly that the Jewish state has an offensive cyberwarfare capability. The acknowledgment came, however, as part of an emphatic assertion that defending against cyberattacks is far more important: “Our goal with cyberdefense, which is the more important and difficult component, is to prevent damage,” he said. “It is more than we can benefit from an offensive action, even though both aspects exist.”