From an article published on October 29, 2021 :
During a town hall last week, when asked whether America would defend Taiwan against a Chinese assault, President Joe Biden answered: “yes.” In response, China’s foreign ministry stated unambiguously that, to prevent the loss of Taiwan, Beijing is prepared to go to war. If China were to attack Taiwan, and the United States sent military forces to Taiwan’s defense, could the United States lose a war with China?
When current Deputy Secretary of Defense Kathleen Hicks and her fellow members of the National Defense Strategy Review Commission examined this question in 2018, they concluded: maybe. In their words, America “might struggle to win, or perhaps lose a war against China.” As they explained, if in response to a provocative move by Taiwan, China were to launch an attack to take control of that island that is as close to its mainland as Cuba is to the United States, it might succeed before the U.S. military could move enough assets into the region to matter. As former Vice Chairman of the Joint Chiefs of Staff Admiral James Winnefeld and former CIA Acting Director Michael Morell wrote last year, China has the capability to deliver a
fait accompli to Taiwan before Washington would be able to decide how to respond.
Former Deputy Secretary of Defense Bob Work, who served under three Secretaries before retiring in 2017, has been even more explicit. As he has stated publicly,
in the most realistic war games the Pentagon has been able to design simulating war over Taiwan, the score is eighteen to zero. And the eighteen is not Team USA.