Biden has now reaffirmed that the United States would defend Taiwan against a Chinese attack and confirmed the statement when asked.
This is effectively a change in US China policy, although the White House again denied it after the President's interview.
In line with the decades-old policy of "strategic ambiguity," the leadership in Beijing could not be certain that America would actually go to war for Taiwan.
Now she has to reckon that at least this supreme commander would do it.
chilling effect
That has a chilling effect, and that's likely to be Biden's calculus.
The Chinese show of strength after Pelosi's most recent visit to Taipei made it clear that Beijing is not afraid of an escalation.
From a strategic point of view, the American attitude in the Ukraine war also plays a role that should not be underestimated: it raises doubts about the willingness to take military action on behalf of friendly states.
The Western sanctions against Russia and the arms deliveries to Ukraine will be followed closely in Beijing.
But they also show that Western solidarity with countries that are not formal allies has limits.
Taiwan is also such a country.
By charting a different course here than in the case of Ukraine, Biden raises the potential stakes for Beijing – but also for America itself.