The speed of the Chinese technologists, compared to United States and European artificial intelligence developers, is noteworthy. Last April, Gansha Wu, then the director of Intel’s laboratory in China, left his post and began assembling a team of researchers from Intel and Google to build a self-driving car company. Last month, the company, Uisee Technology, met its goal — taking a demonstration to the International Consumer Electronics Show in Las Vegas — after just nine months of work.

“The A.I. technologies, including machine vision, sensor fusion, planning and control, on our car are completely home-brewed,” Mr. Wu said. “We wrote every line by ourselves.”

Their first vehicle is intended for controlled environments like college and corporate campuses, with the ultimate goal of designing a shared fleet of autonomous taxis.

The United States’ view of China’s advance may be starting to change. Last October, a White House report on artificial intelligence included several footnotes suggesting that China is now publishing more research than scholars here.

Still, some scientists say the quantity of academic papers does not tell us much about innovation. And there are indications that China has only recently begun to make A.I. a priority in its military systems.

“I think while China is definitely making progress in A.I. systems, it is nowhere close to matching the U.S.,” said Abhijit Singh, a former Indian military officer who is now a naval weapons analyst at the Observer Research Foundation in New Delhi.

Chinese researchers who are directly involved in artificial intelligence work in China have a very different view.

“It is indisputable that Chinese authors are a significant force in A.I., and their position has been increasing drastically in the past five years,” said Kai-Fu Lee, a Taiwanese-born artificial intelligence researcher who played a key role in establishing both Microsoft’s and Google’s China-based research laboratories.

Mr. Lee, now a venture capitalist who invests in both China and the United States, acknowledged that the United States is still the global leader but believes that the gap has drastically narrowed. His firm, Sinovation Ventures, has recently raised $675 million to invest in A.I. both in the United States and in China.

“Using a chess analogy,” he said, “we might say that grandmasters are still largely North American, but Chinese occupy increasingly greater portions of the master-level A.I. scientists.”

What is not in dispute is that the close ties between Silicon Valley and China both in terms of investment and research, and the open nature of much of the American A.I. research community, has made the most advanced technology easily available to China.

In addition to setting up research outposts such as Baidu’s Silicon Valley A.I. Laboratory, Chinese citizens, including government employees, routinely audit Stanford University artificial intelligence courses.

One Stanford professor, Richard Socher, said it was easy to spot the Chinese nationals because after the first few weeks, his students would often skip class, choosing instead to view videos of the lectures. The Chinese auditors, on the other hand, would continue to attend, taking their seats at the front of the classroom.

Artificial intelligence is only one part of the tech frontier where China is advancing rapidly.

Last year, China also brought the world’s fastest supercomputer, the Sunway TaihuLight, online, supplanting another Chinese model that had been the world’s fastest. The new supercomputer is thought to be part of a broader Chinese push to begin driving innovation, a shift from its role as a manufacturing hub for components and devices designed in the United States and elsewhere.

In a reflection of the desire to become a center of innovation, the processors in the new computer are of a native Chinese design. The earlier supercomputer, the Tianhe 2, was powered by Intel’s Xeon processors; after it came online, the United States banned further export of the chips to China, in hopes of limiting the Chinese push into supercomputing.

The new supercomputer, like similar machines anywhere in the world, has a variety of uses, and does not by itself represent a direct military challenge. It can be used to model climate change situations, for instance, or to perform analysis of large data sets.

But similar advances in high-performance computing being made by the Chinese could be used to push ahead with machine-learning research, which would have military applications, along with more typical defense functions, such as simulating nuclear weapons tests or breaking the encryption used by adversaries.

Moreover, while there appear to be relatively cozy relationships between the Chinese government and commercial technology efforts, the same cannot be said about the United States. The Pentagon recently restarted its beachhead in Silicon Valley, known as the Defense Innovation Unit Experimental facility, or DIUx. It is an attempt to rethink bureaucratic United States government contracting practices in terms of the faster and more fluid style of Silicon Valley.

The government has not yet undone the damage to its relationship with the Valley brought about by Edward J. Snowden’s revelations about the National Security Agency’s surveillance practices. Many Silicon Valley firms remain hesitant to be seen as working too closely with the Pentagon out of fear of losing access to China’s market.

“There are smaller companies, the companies who sort of decided that they’re going to be in the defense business, like a Palantir,” said Peter W. Singer, an expert in the future of war at New America, a think tank in Washington, referring to the Palo Alto, Calif., start-up founded in part by the venture capitalist Peter Thiel. “But if you’re thinking about the big, iconic tech companies, they can’t become defense contractors and still expect to get access to the Chinese market.”

Those concerns are real for Silicon Valley.

“No one sort of overtly says that, because the Pentagon can’t say it’s about China, and the tech companies can’t,” Mr. Singer said. “But it’s there in the background.”