Chinese President Xi Jinping vowed to match U.S. President Donald Trump blow for blow in any trade war. Now as one gets closer, some in Beijing are starting to openly wonder whether China is ready for the fight — an unusually direct challenge to the leadership of the world's second-largest economy.

In recent weeks, prominent academics have begun to question if China's slowing, trade-dependent economy can withstand a sustained attack from Trump, a possibility that has already started to weigh on stock prices. The sentiments are being expressed in carefully worded essays circulated on China's heavily censored internet and — according to interviews in recent days with ministry officials and foreign diplomats who asked not to be identified — repeated in the halls of government offices, too.

The essays have raised concerns that the ruling Communist Party underestimated the depth of anti-China sentiment in Washington and risked a premature showdown with the world's sole superpower. Such views push the bounds of acceptable public debate in a nation where dissent can lead to censure or even jail time, and are particularly bold, given Xi has amassed unrivaled control while leading China to a more assertive role on the world stage.