Biden’s threat risks “helping to bring about a Taiwan conflict,” said one foreign policy scholar. “Self-injurious and entirely unforced.”

Critics of U.S. imperialism sounded the alarm Monday after President Joe Biden said that he would use military force in response to a Chinese invasion of Taiwan.

“That’s the commitment we made,” Biden said at a press conference held jointly with Japanese Prime Minister Fumio Kishida during a visit to Tokyo, abandoning the “strategic ambiguity” that U.S. presidents have long maintained to obscure how far Washington would go to protect Taiwan, which China considers part of its territory.

“We agreed with the One China policy, we signed on to it,” said Biden, “but the idea that [Taiwan] can be taken by force… it’s just not appropriate.”

Biden has provided billions of dollars in weapons to help Ukraine stave off Russia’s ongoing military assault but refused to deploy U.S. troops for fear of triggering a direct confrontation between the world’s leading nuclear powers. However, he said Monday, the U.S. would go further on behalf of Taiwan.