As President Trump takes part in a Beijing summit this week with Chinese President Xi Jinping, no issue will be more critical to Xi than Taiwan.

Beijing has called Taiwan the core of China’s core interests, with reunification, even by force, the center of Xi’s agenda.

In many ways, China and Taiwan are similar. They have a shared history, language and culture. But over the last nearly 80 years, Taiwan has become many things that China isn’t. Taiwan, a self-ruled island, is a thriving democracy with a dynamic capitalist economy. It is a place where people express themselves openly without worry.

Fewer than 10% of Taiwan’s population favors reunification with China, according to surveys, and fears it will fall under Communist control are on the rise.

“Since democratization, we have enjoyed the freedom of speech, of democracy, a diversified society,” Taiwan’s deputy foreign minister Chen Ming-chi told CBS News in an interview earlier this month. “We’ve been through an authoritarian past. We see democracy is something we achieved. Taiwanese people cherish that very much. So we will never accept the one country, two systems.”

Taiwan is also one of the largest potential flash points between the U.S. and China, the only place where open warfare between the two powerful militaries is possible. China regularly conducts military exercises around Taiwan in an ongoing show of force.

For decades, U.S. presidents have remained steadfast in their defense of the tiny Asian ally from its neighboring giant. But there’s growing concern that President Trump could change that, which would have implications around the world.

Taiwan is critical to the American economy. It produces more than 90% of the world’s most advanced semiconductors, crucial for artificial intelligence and defense, making it indispensable to the global supply chain.

“There’s a tremendous amount at stake in this relationship,” said Jonathan Czin, a fellow at the John L. Thornton China Center at the Brookings Institution, of the U.S.-Taiwan relationship. “And I don’t think it’s an exaggeration to say that.”

China has seen Taiwan as a breakaway province since 1949, when the nationalists lost the Chinese Civil War to the Communists and fled the mainland.

Today, Taiwan is an economic powerhouse with a per capita GPD that is one of the highest in the world.

For decades, the U.S. has declined to recognize the Chinese Communist Party’s claim over the island and has provided Taiwan with billions of dollars in arms every year, including a $10 billion package announced last December.

But a new $14 billion arms package for Taiwan has been awaiting Mr. Trump’s signature for months. And many in Taiwan fear Xi will use trade deals to weaken U.S. support or change the status quo. What has prompted those fears are Mr. Trump’s recent comments that he is willing to discuss U.S. arms sales to Taiwan with Xi.

“There is definitely concern that he [Mr. Trump] will trade away that arms sale in exchange for something else, you know, whether that’s for assistance on Iran, or some kind of economic concession,” Czin said. “President Trump’s transactional approach is that everything’s up for negotiation.”

Chen Ming-chi told CBS News that he views the U.S. as a “dependable ally,” and is not concerned it will abandon Taiwan.

“The U.S. can count on us as much as we can count on the U.S.,” Chen said. “Do we believe in the U.S. commitment? Yes. They are our reliable partner. Probably the most reliable partner.”