CANAGUINIM, India — Barely an hour into India’s high-profile energy summit in the southern state of Goa, conversation turned to the emergent global order — one without America at the center.

“What is happening in the world today is not a gradual economic transition, it is a rupture,” said Canada’s energy minister, Tim Hodgson, echoing the words of Prime Minister Mark Carney, who electrified the crowd in Davos last week by sounding the death knell of the postwar international system.