On this day in 1945, the first nuclear weapon was used in conflict, with devastating consequences for the people of Hiroshima. In Asia today, nuclear weapons remain part of the strategic reality, for better or worse.

But calculations about nuclear armaments in the region may be changing, notably with the introduction of Chinese and Indian submarine-launched nuclear weapons. This could have profound implications for whether nuclear weapons continue to help keep the peace or become instruments of instability and catastrophic escalation.

Often, strategic analysts and policymakers consider nuclear deterrence as somewhat separate from broader strategic and economic change. This has been all too apparent in the grand maritime region of Indo-Pacific Asia, where economic growth has been accompanied by tensions at sea, military modernisation and growing strategic differences among the powers.

Now, changes in the region are beginning to challenge traditional deterrence dynamics. Throughout the next decade, sea-based nuclear-weapon delivery platforms are set to proliferate in the Indo-Pacific, with China reportedly due to conduct its first at-sea nuclear deterrence patrol sometime this year, India readying for sea-trials of its first nuclear ballistic missile submarine, and even potential Pakistani interest in putting nuclear arms to sea.

Advocates of sea-based nuclear weapons see these fleets as providing stability because of their relative invulnerability to surprise attack. This is meant to provide a secure 'second strike' capability, ensuring that nuclear deterrence is credible and thus successful at preventing war.

But the picture is murky.

The implications of new sea-based nuclear weapons for deterrence, stability or instability will not be determined by those weapons systems alone. Investment in other capabilities like ballistic missile defences, anti-submarine warfare (including nuclear-powered attack submarines) and hypersonic missiles could complicate the picture. And much will depend on doctrines, the professionalism of personnel, and matters of perception and communication.

The nexus between new platforms, the factors driving their introduction and broader strategic realities raises the critical question of strategic stability. Will these new platforms, on balance, add to long-term stability in the region, greatly reducing the incentives for war or escalation, or will they contribute to the risks of crisis, arms races and coercion?

Will the deployment of an assured second-strike capability by India and China in the coming years lead to recognition of mutual vulnerability between them and also between China and the US? Or will sea-based nuclear weapon delivery platforms add to already heightened maritime tensions and risk? How will the shifting dynamics of nuclear deterrence interact with conventional force postures in the region? Are there stability-enhancing lessons to learn from the Cold War experience of the established sea-based nuclear powers?

In the weeks ahead, The Interpreter will host an international online debate to help answer these critically important questions. To open the debate, we have invited contributions from four leading scholars of strategy, maritime security and nuclear deterrence: Bruno Tertrais of the Fondation pour la Recherche Stratégique, Ravi N Ganesh of Asia Centre Bangalore, Wu Riqiang of Renmin University of China and Peter Dombrowski of the US Naval War College.

These initial posts will be followed by contributions from a range of security scholars and practitioners, and there will also be opportunity for the original contributors to reply and expand upon their arguments. Interpreter readers are also invited to join the conversation through the comments section, with the best comments to be featured in special posts. I hope the discussion, like our debate some years ago on extended nuclear deterrence, will prove lively, informative and of genuine value to policymakers.

Most of all, I hope it will help illuminate the way to measures that might minimise the risk that nuclear weapons will ever be used again.

The Lowy Institute gratefully acknowledges support from the John D and Catherine T MacArthur Foundation for this Interpreter debate, which is part of a broader research, dialogue and outreach project on strategic stability in Indo-Pacific Asia

Image courtesy of Wikipedia.