The future of warfare

ADVANCES in military technology have often had momentous effects. The invention of the stirrup enabled mounted warriors to put all the force of the horse behind the spears that they had hitherto thrust with only the strength of their arm. The arrival of that technology in Western Europe in the eighth century soon led to the seizure of church lands and the establishment of feudalism among the Franks. Seven centuries later feudalism was undermined by the longbow, which destroyed the power of horse-owning aristocrats. More recently, the invention of nuclear weapons has brought about a paradoxical peace among superpowers. Now another military revolution is dawning. This one could put the already pre-eminent United States vastly ahead of enemies and allies alike, and thus change the world again.