In the careful grammar of diplomacy, a president's presence on the tarmac speaks before any word is exchanged. Donald Trump's decision to personally greet Chinese President Xi Jinping upon arrival in the United States is a deliberate act of symbolic weight — a signal, amid years of trade friction and geopolitical rivalry, that the two nations' leaders are still willing to stand in the same space and look each other in the eye. Such gestures do not resolve tensions, but they declare an intention to manage them.