I had never traveled south of the equator before. As an American of Pakistani descent, most of my voyages have been easterly, flying high above a fragmenting Europe whose empires once ruled the world, over the cauldron of nations to which the prophets traced the birth of their enduring dogmas, to the dusty, teeming chaos of my ancestral hometown of Peshawar. Those trips to Pakistan were formative. They exposed me to the full spectrum of the human condition, offering lessons in the limits of politics and the realities of geopolitics. Pakistan, after all, had been a front-line state in the United States' war against the Soviet Union in Afghanistan, a war whose implications rippled outward to Peshawar in particular.
But this voyage was different. My friend Hamza and I were flying to Brazil to see the Olympics. We were largely going as tourists, but as an analyst of geopolitics I...