Oppenheimer, father of the atom bomb, fills the screen with his melancholy and quotes Hindu scripture: "I am become Death, the destroyer of worlds."

Apocalypse? Well, maybe. But although the Millennium is almost upon us the threat is less likely to come from the bomb than from communications technologies. Although Saddam may disagree, armies of the future may no longer be armed with bombs and bullets but with hostile software. Stop communications networks and you stop the world. With developed societies across the world depending on the reliable working of communications and control systems, wired dissident groups and hackers may have as much power as the greatest armies.

In Cyberwar, the first programme in the prime-time series Digital Planet, Dr Stephen Badsey, Senior Lecturer at Sandhurst, claimed that "Waterloo was the last major conventional battle conforming to 1,000 years of history. Julius Caesar could have commanded that battle."

In just a hundred years, the nature of battle and the role of the individual soldier has changed completely. The industrial age has given way to the information age. Nation states and national security have become highly vulnerable, and frontiers can now be crossed silently using electronics rather than tanks and aircraft.

Cyberwar demonstrates how the US is becoming aware of the threat of an electronic Pearl Harbour - an abrupt attack on communications systems halting the stock market, emergency services, air traffic control and the utilities. Soon after the Gulf War, researchers at the US think-tank, the Rand Corporation, announced that national armies were as redundant as Henry Ford's production line. Their paper Cyberwar is Coming asked the crucial question `Do numbers make the difference on a battlefield or does knowing?'

But, as Churchill remarked, it's better to "jaw-jaw than war-war" and Cybertalk explores whether the new communications technologies are actually changing the way we talk to each other. Language makes us human and our social, emotional and political lives depend on our use of speech to form new alliances and defend our territory.

In the world of the mobile phone, video-conferencing and the Internet, our communications seem to defy time and space. We are certainly greedy to extend our communities but are our conversations improving in quality or just increasing in frequency?

With e-mail, voice-mail and junk mail, have we really found a better substitute for the conversation over the garden fence or on the street corner? Cybertalk takes a look at Microsoft's experiment in wiring up a London street and asks whether new technology can actually strengthen a sense of community. Residents share advice on growing acacias with gardening enthusiasts across the Pacific but do residents still borrow sugar and talk face to face? If e-mail is the most impoverished form of communication why has it been so successful?

In the Western Isles, communications technology is used to keep communities together. Tiny primary schools now access specialist teaching in drama, music and art through the phone line and the computer screen. The kind of teaching only previously available on the mainland now reaches the most isolated village.

We now live in a kind of communications soup with different forms of contact swirling around rather than replacing each other. How different are the prophets of the Internet from those who predicted that the Victorian Internet - the telegraph - would create information overload?

As Tom Standage, Science Editor of The Economist, says "Information overload really happened for the first time in the 1860s when business really woke up to the telegraph. Once a business had it, all other businesses had to adopt it because otherwise they couldn't compete."

Effective communications will always determine whether organisations survive, but we are still unsure about the ultimate benefits. As the OU's Chris Dillon says: "Corporations can't predict the future - stories about the inevitability of technology, how it will improve our lives, are all just stories - we don't have to believe them.'

In a world of smart cards and smart buildings, will we soon have smart people? Now we can talk across continents and live and play in virtual realities, the programme Cybersouls asks what are the boundaries of our bodies in the digital age?

Stelarc, a performance artist, is shown connecting his body to the Internet with digital data converted into electrical charges to make him move involuntarily. Is he a wired body or a fleshed machine?

Researchers are also exploring genuine mergers of human beings with technology. Kevin Warwick, Professor of Cybernetics at Reading University, implanted a silicon chip into his arm for a computer to map his movements and sensations. When the chip was removed he mourned the loss of what seemed to be an extra faculty but senses real danger. "If we give machines enough power, if they can communicate across the Internet, then we have distinct problems - this could mean that we lose control ultimately and the Internet and machines are in control themselves."

Cybersouls takes us into a new realm of ethics where Koestler's `ghost in the machine' may have been expelled completely in an emerging world of digital flesh. Researchers at MIT are already designing `wearable technology.' Steve Mann, self-styled `cyborg' at the University of Toronto, reads his e-mail and transmits his view of the world via a computer screen and tv camera miniaturised into his spectacles.

If we can extend our senses and bodies with technology and intelligent machines can make decisions by leaving us out of the loop altogether, will we become second class citizens? The digital world already has a grip on us, recording our actions. Through our credit cards, bank accounts, insurance and health records we are leaving a distinctive data trail behind us

Digital Planet shows us why our pre-millennial tension is justified. It also reminds us we have choices to make about the future.

The second and third episodes are shown on BBC2 on the next two Mondays. The series will then be repeated in the small hours during February - see next month's Open Eye for details.