London

THE decision by the United States and Israel to develop and then deploy the Stuxnet computer worm against an Iranian nuclear facility late in George W. Bush’s presidency marked a significant and dangerous turning point in the gradual militarization of the Internet. Washington has begun to cross the Rubicon. If it continues, contemporary warfare will change fundamentally as we move into hazardous and uncharted territory.

It is one thing to write viruses and lock them away safely for future use should circumstances dictate it. It is quite another to deploy them in peacetime. Stuxnet has effectively fired the starting gun in a new arms race that is very likely to lead to the spread of similar and still more powerful offensive cyberweaponry across the Internet. Unlike nuclear or chemical weapons, however, countries are developing cyberweapons outside any regulatory framework.

There is no international treaty or agreement restricting the use of cyberweapons, which can do anything from controlling an individual laptop to disrupting an entire country’s critical telecommunications or banking infrastructure. It is in the United States’ interest to push for one before the monster it has unleashed comes home to roost.

Stuxnet was originally deployed with the specific aim of infecting the Natanz uranium enrichment facility in Iran. This required sneaking a memory stick into the plant to introduce the virus to its private and secure “offline” network. But despite Natanz’s isolation, Stuxnet somehow escaped into the cyberwild, eventually affecting hundreds of thousands of systems worldwide.