As Japanese Prime Minister Sanae Takaichi arrives in India for the 16th annual India-Japan Summit, to observers, the warmth between India and Japan can look like a marriage of convenience — two democracies hedging against the same continental power, drawn together by the arithmetic of the Indo-Pacific. But strategic alignment of this depth and durability rarely rests on arithmetic alone. Beneath the joint statements and the carrier diplomacy lies a shared philosophical disposition toward the modern world, and to name it one must reach for a Japanese phrase: wakon yōsai — ‘Japanese spirit, Western technique’. Understanding this idea is the key that unlocks why Delhi and Tokyo so instinctively understand each other...