Two years ago liu Yunshan, the visiting Chinese dignitary, and Kim Jong Un, the North Korean leader, tried to put on a show of friendship, chatting amiably as the cameras rolled, but just as often they stood silent, staring ahead as a military parade passed before them.
The stretch of time is a sign of the distance between two nations with a torturous history: one a rising power seeking regional dominance, the other an unpredictable neighbor with its own ambitions.
China has made little secret of its long-term goal to replace the United States as the major power in Asia and assume what it considers its rightful position at the center of the fastest-growing, most dynamic region in the world.
But North Korea, which defied Beijing by testing a sixth nuclear bomb on Sunday, has emerged as an unexpected and persistent obstacle.
Other major hurdles litter China's path. The United States, despite signs of retreat in Asia under the Trump administration, remains the dominant military power. And India and Japan, China's traditional rivals in the region, have made clear that they intend to resist its gravitational pull.