Under Joe Biden, the longstanding American policy of ‘strategic ambiguity’ vis-à-vis Taiwan has taken on a curious post-modern quality. The official US position on arguably the biggest international question of the moment is now so ambiguous that even the president of the United States doesn’t appear to know what it is.

In a long interview with CBS 60 minutes this weekend, president Biden was asked if US forces would defend Taiwan in the event of a Chinese attack. ‘Yes,’ he replied. ‘If in fact there was an unprecedented attack.’ The White House promptly clarified that, in fact, the US position has not changed, suggesting that America still might not commit to defending Taiwan with its own troops.

The same thing happened in May. At a press conference in Tokyo, Biden said America would defend Taiwan only for the White House to reiterate that America’s ‘one China policy’ hadn’t changed. The One China policy – which Biden acknowledged in his CBS interview – means that America does not challenge China’s claims over Taiwan.

So, there you have it. America will defend Taiwan militarily from a Chinese invasion. Also, it might not.

China, for one, appears to be taking Biden’s remarks more seriously than his own office. A Chinese foreign ministry spokeswoman has said that Biden’s comments send a ‘seriously wrong signal’ and that China was ‘strongly dissatisfied and resolutely opposed’ to Biden’s remarks. The Chinese were vociferously furious in August when House Speaker Nancy Pelosi visited Taiwan, a trip about which the White House was reportedly uncomfortable.

Biden, an old man, often says words he doesn’t really mean. And his doddering can have strategic advantages – less the ‘mad man’ theory of diplomacy, more the senile one.

Yet ambiguity is one thing; muddle is another, and the issue goes deeper than Biden’s loquaciousness. America’s ambiguous stance on Taiwan has become increasingly untenable as China becomes increasingly belligerent about the islands under the hawkish leadership of Xi Jinping.

At some point, surely, Uncle Sam will have to draw a red line for Xi to either cross or not. The president cannot keep saying one thing only for the White House to suggest another.