Chinese leaders stretching back to Deng Xiaoping have often thought in terms of decades. A decade encompasses two of China’s famous five-year plans, and it’s a long-enough period to notice real changes in a country’s trajectory.

As it happens, I spent time in China at both ends of the decade that just ended, first in 2010 and again recently. And I was left with one main conclusion: China has just enjoyed a very good decade.

Yes, it still has big problems, including the protests in Hong Kong. But by the standards that matter most to China’s leaders, the country made major gains during the 2010s. Its economy is more diversified. Its scientific community is more advanced, and its surveillance state more powerful. Its position in Asia is stronger. China, in short, has done substantially more to close the gap with the global power that it is chasing — the United States — than seemed likely a decade ago.

Many Americans, of course, understand that China is on the rise and are anxious about it. Yet I also returned from my trip thinking that this American anxiety tends to be misplaced in one crucial way: China is not preordained to supplant or even match the United States as the world’s leading power. China’s challenges are real, not just the protests in Hong Kong but also the dissent in Xinjiang and Tibet, the bloat in its state-run companies and the looming decline in its working-age population.