Technology has always been a double-edged sword, empowering both our creative and our destructive natures. It has brought us longer and healthier lives, freedom from physical and mental drudgery, and many new creative possibilities. Yet it has also introduced new and salient dangers.

Stalin’s tanks and Hitler’s trains used technology. And we still live today with sufficient nuclear weapons—not all of which appear to be well accounted for—to end all mammalian life on the planet.

Bioengineering is set to make enormous strides in reversing disease and aging processes. However, the means and knowledge to create unfriendly pathogens more dangerous than nuclear weapons will soon exist in most college bioengineering labs. As technology accelerates toward the full realization of genetic engineering, nanotechnology and, ultimately, robotics (collectively known as GNR), we will see the same intertwined potentials: a feast of creativity resulting from human intelligence expanded manyfold, combined with grave new dangers. We need to devise our strategies now to reap the promise while we manage the peril.

Consider unrestrained nanobot replication. Nanobot technology requires the coordinated operation of billions or trillions of intelligent microscopic devices to be useful. The most cost-effective way to scale up to such levels is through self-replication, essentially the same approach used in the biological world. But in the same way that biological self-replication gone awry results in biological destruction (cancer, for example), a defect in the mechanism that safely controls nanobot self-replication would endanger all physical entities, biological or otherwise.

The threats of nanotechnology don’t stop there. We must also worry about control and access. Organizations, governments, extremist groups or just a clever individual could create havoc with this technology. For example, one could put trillions of undetectable nanobots in the water or food supply of an individual or an entire population. These "spy" nanobots could then monitor, influence and even control our thoughts and actions. Existing "good" nanobots could be influenced through software viruses and other hacking techniques. When there is software running in our brains, issues of privacy and security will take on a new urgency.

People often go through three stages in examining the impact of future technology: awe and wonderment at its potential to overcome age-old problems; then a sense of dread at a new set of dangers that accompany the new technology; followed, finally and hopefully, by the realization that the only viable and responsible path is to set a careful course that can realize the benefits while managing the risks.