ow does Joe Biden lose? Dozens of national and swing-state polls dating back to the spring have consistently given him a winning lead. Nearly all now predict Biden will defeat Donald Trump handily on 3 November. Depending on how key states break, it could be a landslide – plus a Democratic clean sweep of Congress. Even if the polls are as wrong as they were in 2016, Biden, whose national lead is 10%, is still projected to win the popular vote by 7%. He still wins battleground states such as Pennsylvania, Florida and Arizona and, with them, the electoral college that was Hillary Clinton’s undoing four years ago. All Trump’s clumsy and divisive efforts to change the dynamic of the race have failed so far. His Covid-19 histrionics won him scant sympathy. It seems the die is cast. So, assuming the polls are not totally off, what could go wrong for Biden? One risk, given his age, 77, is that he becomes unwell, either from Covid or some other cause. That would not disqualify him, but it would undermine confidence in his fitness to lead. Or Biden could make a trademark gaffe, though it would have to be truly egregious to matter. More plausible scenarios are that deliberate fraud or sheer incompetence skew the election outcome or, if the result is close, Trump refuses to accept defeat and wins in the supreme court, as George W Bush did in 2000. But another elephant trap lurks: the risk that an international crisis could erupt – by accident or design – allowing Trump to pose as the nation’s doughty defender while sidelining Biden. The more desperate Trump gets, the higher the risk of this happening. China needs watching closely right now. Its hawkish dictator-president, Xi Jinping, has over-reached, and faces possible push-back at home. Yet on past evidence, he will double down – in order to reassert his post-virus authority and justify his increasingly counter-productive hardline policies. If push comes to shove, Xi could turn on the US. Xi has come a long way since he stood smiling in the White House Rose Garden alongside Barack Obama in September 2015, and promised a new era of bilateral friendship. “China is committed to the path of peaceful development and a foreign policy characterised by good neighbourliness and partnership,” he declared. China believed “democracy and human rights are the common pursuit of mankind” and respected international law, national sovereignty and freedom of navigation, he said. “China does not intend to pursue militarisation” of the South China Sea. Yet since then, China’s behaviour has grown steadily more aggressive and lawless. Xi has picked fights with India, Australia and European countries, crushed democracy in Hong Kong, reduced domestic freedoms, and tightened the state’s chokehold on Tibetans and Xinjiang’s Uighurs. His South China Sea pledge proved meaningless. US attitudes have changed radically too. Trump’s damaging trade war, sanctions, and “China virus” rhetoric have turned supposed amity into open hostility. In particular, Trump’s weapons sales and stepping up of diplomatic and military support for Taiwan have infuriated Xi, who has vowed to recover the “renegade province” by any and all means. Deteriorating relations have meanwhile accelerated debate in Washington about ending the 40-year-old policy of “strategic ambiguity” over whether the US would fight for Taiwan if it were attacked. Richard Haass, an influential foreign policy veteran, argues only a clear US pledge to intervene will deter China and its ever-more formidable military. “There is speculation that Xi will marry his ambitions with the new means at his disposal to realise his ‘China Dream’ and force reunification with Taiwan, potentially as soon as 2021. No one should dismiss the possibility that Taiwan could become the next Hong Kong,” Haass warned. Current US policy was untenable, wrote conservative columnist George Will. “China is demonstrating the arrogance that begets recklessness... Taiwan might provide the most perilous US moment since the Cuban missile crisis.” Concern that US attitudes are hardening and that Washington is actively encouraging Taiwanese defiance – potentially thwarting the putative crowning achievement of Xi’s reign – has produced a rising torrent of threats, aerial incursions, invasion drills, and vitriolic sniping from Beijing in recent weeks. “The militaristic tone reflects the hawkishness of Xi. The risk is that the propaganda could translate into more provocative actions... Recent military moves in the South China Sea and the Taiwan Strait raise the possibility of actual clashes, intended or not,” the New York Times’s Steven Lee Myers reported. Never one to dial down confrontation, US secretary of state Mike Pompeo was in Tokyo last week, cranking up the “China threat”. The American focus is on 2021. But what if Xi decided to make a move now, at a moment of maximum US distraction and vulnerability, when Pentagon chiefs are in isolation and Trump’s eccentric behaviour grows ever more bizarre? In such an emergency, Biden’s preferred policy of dealing with China through verbal strictures, dialogue and alliances might look lame. Xi probably has no wish to help Trump get re-elected. And he will surely not risk a head-on collision if he’s thinking clearly. But given internal pressures, and his post-2015 record of unchecked aggression, no one knows which way he will jump. Xi may calculate that now is his best chance to force the Taiwan issue. Trump has long accused Biden of being soft on China. If a crisis with Beijing erupted by chance, or were deliberately provoked by either side, he is not above exploiting it electorally to make the Democrat look weak and himself strong – even if doing so risks a war. Biden must hope the guns stay silent.