China’s state-run Global Times newspaper on Monday said President-elect Donald Trump is “as ignorant as a child” when it comes to foreign relations.

{mosads}“Many people might be surprised at how the new U.S. leader is truly a ‘businessman’ through-and-through,” the editorial said, as reported by The Associated Press. “But in the field of diplomacy, he is ignorant as a child.”

Trump broke decades of diplomatic protocol when he spoke with Taiwan President Tsai Ing-wen over the phone. The U.S. and Taiwan severed diplomatic relations in 1979.

The call sparked outrage in China, and Fox News reported Monday that China flew a nuclear-capable bomber over the South China Sea to send a message to the president-elect.

“China needs to launch a resolute struggle with him,” the Global Times editorial said. “Only after he’s hit some obstacles and truly understands that China and the rest of the world are not to be bullied will he gain some perception.”