John Bolton issued a warning Tuesday about why he believes Donald Trump’s tariffs are a “form of economic illiteracy” that will actually present “a huge opportunity for China worldwide.”

“Trump has no idea really what he’s talking about,” Bolton told CNN’s Anderson Cooper, adding: “He doesn’t understand how tariffs work. He has said as recently as a few days ago, he views trade surpluses and deficits as like a profit and loss statement, which they certainly are not.”

Trump has put the U.S. in “a very vulnerable position,” continued Bolton, who served as a national security adviser during Trump’s first term but has since become one of the president’s outspoken critics.

“Instead of taking on the country [China] that’s stolen our intellectual property for decades, among other things, by gathering our allies together, all of whom also suffer from China’s intellectual property theft and engaging in concerted action, we’re at war with our largest trading partners while we’re about to go to war with China as well,” he explained.

“It simply makes no sense and it’s just sad and depressing that more Republicans haven’t stood up and said that this is illiteracy,” he added.

Trump’s tariffs — including a 104% levy on Chinese imports — came into effect Wednesday. China’s foreign ministry said it will take “resolute and forceful” measures in response.