Historically, technological change has altered how battles are fought but has not overturned the fundamental principles of war. However, three considerations may now represent an actual revolution: the recourse to tactical nuclear weapons, the development of software for “multi-domain operations,” and the prospect of general artificial intelligence. The organization of militaries and the use of force need to be rethought in this light.

Historically, technological change has altered how battles are fought but has not overturned the fundamental principles of war. However, three considerations may now represent an actual revolution: the recourse to tactical nuclear weapons, the development of software for “multi-domain operations,” and the prospect of general artificial intelligence. The organization of militaries and the use of force need to be rethought in this light.

The arms control system built during and after the Cold War is under enormous stress and is fraying at the edges. It once enabled significant improvements in international security but is in danger of not withstanding the resurgence of tensions in recent years. Urgent action is now needed to prevent the proliferation of nuclear, chemical, and biological weapons, as well as cluster bombs and anti-personnel mines.

It is tempting to conclude that international law’s influence is receding in a context where power struggles are in the ascendant, especially between dominant nations. But the law still carries weight: as the ultimate constraint on the use of violence, as a shared language for all human communities, and as a framework for action for those who seek to invoke it. It doubtless needs to be rethought and adapted to changes in international relationships, but without losing sight of its day-to-day importance.