More: The 747 slowly wheeled to a stop last night on the tarmac of Joint Base Andrews, just outside Washington. Portable stairs were put in position, while a red carpet was unfurled and lined by both American and Chinese soldiers in dress uniforms. After a few minutes, Chinese President Xi Jinping appeared at the aircraft door. He paused and waved. Waiting below, staring up expectantly, was President Trump.

It was a remarkable act of deference. By tradition, American presidents don't make the 12-mile trip to the base to greet a foreign leader. They instead wait at the White House, backed by the grandeur and power of the executive mansion. But not this time.

Xi did not display the same level of hospitality when Trump visited Beijing in May, and the U.S. president's gesture suggested that he will take a conciliatory role during the closely watched summit between the leaders of the world's foremost superpowers. Trump is not expected to push Xi on core issues, including the pace of artificial-intelligence development, Taiwan's defense, and China's support for Iran in its war with the United States.

It was not that long ago when Trump, a self-styled international bully, could credibly claim to "run the country and the world." But he seems far smaller on the global stage now.