India, June 16 -- When Ursula von der Leyen stood beside Narendra Modi in New Delhi on January 27 and called the EU-India trade deal "the mother of all deals," the phrase landed with the kind of finality that large diplomatic moments tend to produce. Eighteen years of on-and-off negotiations, collapsed in the best possible way. The photographs were warm. The joint statement was long. And both sides went home having accomplished something genuinely significant, which is also, in the EU-India story, precisely the moment when the real difficulties begin.

A trade deal concludes negotiations. It does not create a relationship. The EU and India have had a strategic partnership since 2004, a Trade and Technology Council since 2022, and bilatera...