DETROIT — China’s flag flies high above Henniges Automotive, alongside those of Germany, Mexico, Canada and other nations, reflecting the global nature of Michigan’s auto industry and, increasingly, its reliance on Beijing.

Henniges, which produces sealing products for cars, was bought in 2015 by the Aviation Industry Corporation of China, a state-owned company that has snapped up other investments in the Detroit area, including the automotive supplier Nexteer, which sits just across Interstate 75 from Henniges. Over the past several years, Beijing has steadily pumped billions of dollars’ worth of investment into Michigan, buying crumbling factories, building new ones and supporting more than 10,000 jobs in the state.

But where Michigan sees an economic partner, President Trump sees an “economic enemy” — one intent on overtaking America’s competitive edge by stealing technology, trade secrets and jobs from domestic companies. As Mr. Trump tries to punish China with tariffs and other restrictions, Michigan is caught in the cross hairs, with its ability to remain competitive and develop emerging technologies like autonomous vehicles, robotics and artificial intelligence highly dependent on ties to international markets, including China.

“The automotive industry is a global industry,” said Michael O’Kronley, a top executive at A123 Systems, an electric vehicle battery maker purchased out of bankruptcy by the Chinese company Wanxiang in 2013. “If you’re going to supply products into that, you need to be global.”