Paul Mozur

Chinese firms have become significant investors in American start-ups working on cutting-edge technologies with potential military applications. The start-ups include companies that make rocket engines for spacecraft, sensors for autonomous navy ships, and printers that make flexible screens that could be used in fighter-plane cockpits. Many of the Chinese firms are owned by state-owned companies or have connections to Chinese leaders. The deals are ringing alarm bells in Washington.

According to a new white paper commissioned by the Department of Defense, Beijing is encouraging Chinese companies with close government ties to invest in American start-ups specializing in critical technologies like artificial intelligence and robots to advance China’s military capacity as well as its economy. The white paper, which was distributed to the senior levels of the Trump administration this week, concludes that United States government controls that are supposed to protect potentially critical technologies are falling short, according to three people knowledgeable about its contents, who spoke on the condition of anonymity.

Well before the 2016 American election threw Facebook’s status as a digital-era news source into the spotlight, leaders, advocacy groups and minorities worldwide have contended with an onslaught of online misinformation and abuse that have had real-world political repercussions. And for years, the social network did little to clamp down on the false news.

Now Facebook, Google and others have begun to take steps to curb the trend, but some outside the United States say the move is too late. “They should have done this way earlier,” said Richard Heydarian, a political analyst in the Philippines, one of Facebook’s fastest-growing markets. “We already saw the warning signs of this years ago.” The impact of Facebook and other social media platforms on international elections is difficult to quantify. But Facebook’s global reach — roughly a quarter of the world’s population now has an account — is difficult to deny, political experts and academics say.