Autonomous weapons are a game-changer

MANY OF THE trends in warfare that this special report has identified, although worrying, are at least within human experience. Great-power competition may be making a comeback. The attempt of revisionist powers to achieve their ends by using hybrid warfare in the grey zone is taking new forms. But there is nothing new about big countries bending smaller neighbours to their will without invading them. The prospect of nascent technologies contributing to instability between nuclear-armed adversaries is not reassuring, but past arms-control agreements suggest possible ways of reducing the risk of escalation.