The Northrop Grumman B-2 Spirit is a terrifying piece of military kit. The stealth bomber can fly undetected for many thousands of miles to drop a thermonuclear bomb on pretty much any target on the planet. According to one government estimate, each B-2 in operation on average has cost the US Air Force $2.1bn to develop and deploy.
Clearly, very few countries have the money or the technology to invent such weapons systems. There are also very few occasions on which such weapons can be used (God willing). The US therefore remains dominant in what it terms its first and second offset strategies: clear supremacy in nuclear weapons and precision-guided missiles. But although such technologies remain necessary to offset the challenges of rival powers, they are no longer sufficient in our rapidly changing world.
Most defence spending in Nato countries still goes on crazily expensive metal boxes that you can drive, steer, or fly. But, as in so many other areas of our digital world, military capability is rapidly shifting from the visible to the invisible, from hardware to software, from atoms to bits. And that shift is drastically changing the equation when it comes to the costs, possibilities and vulnerabilities of deploying force.