Fifty years ago, my father, an American war reporter, climbed over the wall of the U.S. Embassy in Saigon and scrambled onto a chopper that took off from a roof in the mission.

“My last view of Saigon was through the tail door of the helicopter,” he wrote in the Chicago Daily News. “Then the door closed — closed on the most humiliating chapter in American history.”

My father believed in the domino theory, how a cascade of Communism might deluge Asia. A veteran of World War II, he wrote a book titled, without much irony, “Not Without the Americans.”

The title seems an anachronism, from a time when paternalistic Americans, confident in their own flawed democracy, envisioned a world shaped in their own image. Half a century after the pullout of the last American troops from Vietnam, it’s clear how Asia is learning to live, if not without the Americans, then with a new great power: China.

Beijing’s imprint is everywhere, from the contested waters of the South China Sea, where delicate coral reefs have been churned up to build Chinese military bases, to remote villages in Nepal, where Chinese goods are flooding markets via Chinese-built roads.

A Chinese Coast Guard ship firing a water cannon at a Philippine Navy chartered vessel that was conducting a routine resupply mission last year to troops stationed at Second Thomas Shoal in the South China Sea.Credit…Ezra Acayan/Getty Images