When I joined India’s foreign service four decades ago, the world was still ordered by the Cold War. From the vantage of my first posting in Moscow, I watched the Berlin Wall fall, the Cold War end and the Soviet Union dissolve. History was moving beneath our feet, and we novice diplomats were its quiet witnesses, emphasis on quiet.

Diplomacy, sometimes called the second-oldest profession, has always been the management of difference between strangers who cannot afford to go to war. Its instruments—the démarche, the negotiation, the carefully weighed communiqué—were built for a world of secrecy, hierarchy, and patience. That world is passing. In its place has arrived a newer diplomacy of posts, likes, and live streams, conducted in full public view and at the speed of the feed. Diplomatic actors are expected to perform on this stage, and millions of commentators critique, all in real time.