Trump is ramping up tensions with China in a much bigger way than the trade war
US First Lady Melania Trump (R) and US President Donald Trump (2nd R) welcome Chinese President Xi Jinping (2nd L) and his wife Peng Liyuan (L) to the Mar-a-Lago estate in West Palm Beach, Florida, on April 6, 2017. / AFP PHOTO / JIM WATSON

Much attention has been devoted to President Donald Trump's trade war with China, which is projected to collectively make both nations $455 billion poorer.

But that may not even be the biggest foreign policy crisis Trump is triggering with China. According to Business Insider, Trump may be threatening the One China policy that makes cooperative policy between the two nations possible.

Last week, Trump moved to approve a $2 billion sale of arms to Taiwan, a move that seems calculated to enrage China. While previous administrations have also sold arms to Taiwan, this sale is particularly large and comes at a tense moment in U.S./China relations. Former Assistant U.S. Secretary of State for East Asian and Pacific Affairs had a blunt reaction: "Taiwan is the thing the Chinese care most about hands down ... Anything where the US is interfering with Taiwan hits a national third rail."

Taiwan is where the government-in-exile of the Republic of China fled when the Communists took over the mainland country. It was for a long time considered to be, and still claims to be, the legitimate government of China.

The United States adopted the One China policy in the 1970s, recognizing Taiwan as part of China, to thaw relations between the two countries. But since Trump has taken office, he has challenged U.S. adherence to One China, signing a bill last year that allows U.S. officials to talk with Taiwan.

Around the same time, Taiwan renamed its unofficial embassy in Washington from the "Coordination Council for North American Affairs" to the "Taiwan Council for U.S. Affairs," a name that much more directly implies the two governments have or will have diplomatic relations.

All of this is unlikely to make China receptive to Trump's trade negotiations, or to anything else.