New Delhi, Oct. 22 -- For India and Japan, the next security challenge is not simply how to deter a crisis, but how to remain operational when a crisis disrupts the systems that sustain national power. Warships, missiles and defense budgets matter, but their effectiveness ultimately depends on fuel, critical components, repair facilities, ports and supply chains. A prolonged disruption to these systems can constrain strategic choices without a single shot being fired.

This is why India-Japan security cooperation needs a broader concept: strategic endurance. It is the capacity to sustain economic and military power when essential supplies, infrastructure and production networks come under pressure. Recent cooperation between New Delhi and...