If Donald Trump has wanted to project optimism at the start of his summit with Xi Jinping, the Chinese president has made clear from the first moment what his main red line is. He warned during the meeting that mismanagement with Taiwan could push China and the United States towards a scenario of collision or even conflict, in one of the harshest warnings publicly issued in this new contact between the two powers.
For Beijing, Taiwan is not just another diplomatic issue. China considers the island part of its territory and maintains reunification as a political objective. That approach turns any US move regarding Taiwan into an extremely sensitive issue.
Washington's arms sales, political contacts with Taipei and any gesture interpreted as support for Taiwanese independence are systematically rejected by China.
Why the message matters so much
Xi's warning is not an isolated phrase. It comes in a context in which China had already publicly hardened its discourse even before the meeting. Chinese authorities reiterated on the eve of the summit their outright opposition to any external support for Taiwanese independence. This makes the Chinese president's statement a continuation of a strategic position, not a specific outburst.
Washington has maintained for decades an ambiguous, but active, position regarding Taiwan. The United States does not formally recognize the island's independence, but it does maintain political and commercial ties and approves arms sales.
That balance has been a permanent source of tension with Beijing. The concern now lies in how far any change in that equation could trigger a larger crisis.
A tension that transcends Asia
The potential risk does not affect only the region. A clash between China and the United States over Taiwan would have a direct impact on global trade, supply chains, technology, defense, and international stability.
Among all the disagreements between both powers, Taiwan continues to be the most explosive issue. There may be trade truces, business advances, or partial understandings on other matters, but the room for negotiation on Taiwan is much narrower.
And that explains why, even at a summit with public messages of optimism, Xi wanted to set from the beginning what he considers the limit that Washington must not cross.