BEIJING — Vice President Mike Pence’s accusations in a stinging speech Thursday warning of a tougher approach toward Beijing may have been familiar to China’s leaders. But until now, such remarks were delivered in private, in fairly decorous terms, and rarely threatened direct action.

The surprise this time for Beijing was the magnitude of alleged offenses piled up in one public indictment, ranging from suspected interference in American politics to China’s stomping on the freedoms of its own people. Nor had the United States ever before told China: “We will not stand down.”

Publicly, China responded with a certain weariness, calling the speech “very ridiculous,” creating “something out of thin air,” but also warning that “no one can stop” the Chinese people from advancing.

Behind closed doors, however, Mr. Pence’s remarks probably left few doubts among China’s leaders that Washington was embarking on a Cold War that would force the country to dig in for a prolonged multifront battle with the United States, analysts said.