We left the summit building without saying much. The early evening light in Paris had a way of softening the edges of the streets, even the busy ones. The river caught the last streaks of the sun, turning them into long ribbons of gold on the water. I was aware of Julian beside me, his pace matched to mine, his hands tucked loosely in his coat pockets.

I thought I would feel relief after the talk, the kind that comes when something you’ve been building toward is finally done. Instead, there ...