Trump-Xi’s China summit is a defining test for America in the new Cold War

When Chinese President Xi Jinping publicly declared that mastery of artificial intelligence is "the front line and main battlefield of international competition," he was not indulging in political theater. He was announcing the strategic framework now guiding Beijing’s economic, military and technological ambitions.

After 24 years in uniform and another two-plus decades studying America’s adversaries — from the Pentagon to a think tank to writing 14 books on geopolitical threats — I have...