High-stakes risk has been a hallmark of Elon Musk’s career: defying industry standards with reusable rockets at his $210 billion interplanetary exploration company SpaceX—or, at $1 trillion Tesla, spending billions on titanic production facilities to manufacture electric-vehicle components in-house.

But it was Musk’s recent zero-sum bet to stake his reputation, his newly purchased social media platform, and more than $130 million in political donations to Republicans and Donald Trump’s third presidential campaign that has propelled him—and his companies—to an unparalleled level of power and influence in both business and politics.

Musk, whose sometimes callous opinions and tweets have made him a polarizing figure, was already immersed in international politics. With SpaceX, which is one of the Department of Defense’s most important contractors, Musk has special security clearance, and his satellite network Starlink has played a critical—if sometimes controversial—role in the ongoing Russia-Ukraine conflict.

But in President-elect Donald Trump’s White House—so long as Musk and the incoming POTUS continue to get along—Musk will have Trump’s ear. He’ll know Trump’s cabinet. And he’ll have access to the heads of all of Trump’s regulatory agencies, some of whom will be overseeing his constellation of companies that span the artificial intelligence, space, solar, brain implant, tunneling, and electric-vehicle industries. Musk may even get his own seat at the table—as head of a new “government efficiency commission”—all of which would heighten his power both locally and abroad.

“If you are best friends with the president of the United States, you have access to any world leader you want,” says Darrell West, a senior fellow of governance studies at the Brookings Institution.

As Trump assembles his new team, the extent of Musk’s influence will be on full display. The world will be waiting to see if Trump makes moves in artificial intelligence that benefit xAI or backs off his harsh campaign-trail stance on EVs that collides with Musk’s personal interests. The president-elect has also threatened to impose tariffs on all vehicle imports from China and Mexico, though Tesla has an important gigafactory in Shanghai and has been working to open one near Monterrey. Musk told shareholders in July that Tesla’s Mexico plans were “on pause” as a result of the potential Trump tariffs.

Musk was reportedly already asking for favors even before Trump won the election, with the New York Times writing that Musk asked him to hire some SpaceX employees for government positions. (Representatives for Musk and President-elect Trump did not respond to a request for comment.)

Will Musk’s period of heightened influence last in the next four years, or will the two men’s histories of erratic behavior and obsession with the center stage clash once Trump returns to the Oval Office? Either way, Musk’s innovative spirit—and his intuition on which risky bets are worth taking—has turned him into the most powerful person in business.

This article appears in the December 2024/January 2025 issue of Fortune.

How Elon Musk became the most powerful person in business