In Washington this week, two of the world's most consequential leaders will sit across from one another, carrying the weight of a rivalry that touches nearly every dimension of modern life — from the algorithms shaping human thought to the geopolitical fault lines of the Middle East. The Trump-Xi summit arrives not as a resolution but as a reckoning, a moment when the distance between two civilizations must at least be measured, if not bridged. History will note that they met; what it records beyond that depends on whether direct dialogue can accomplish what years of lower-level negotiation ha