There is no point trying to deny it any longer: the election of Donald Trump has made the world a much more dangerous place.
Suppose you are a national leader with ambitions that run counter to the interests of the US or of the Western powers more generally. With the EU in disarray, and a buffoon in the White House, what better opportunity will you have to put your plans into action?
That's why I strongly suspect that in Moscow, Ankara, Beijing and Pyongyang, the orders have been given: 'Let's move now. We may never get a better chance.'
What scares me most about Trump is not only that he is a deeply unpleasant man with deeply unpleasant views but also that he is grotesquely, frighteningly incompetent and woefully unprepared for the task ahead. His reputation as a successful businessman is as phony as everything else about him, and he is a man who has no experience whatsoever of politics even at the very lowest level, who apparently had no idea of what was involved in putting together a new White House team.
More than a week after his election, no one from his team had been in touch with either the State Department or the Pentagon, and when the Japanese prime minister Shinzo Abe became the first foreign leader to meet him since the election, none of the Japanese leader's aides could find anyone on the Trump team to brief them ahead of the meeting. (After they met, Mr Abe called the president-elect a man in whom he has 'great confidence', which suggests both his well-honed diplomatic skills and his love for whistling in the dark.)
Trump is the man - and this is the team (his daughter and son-in-law were both with him when he met Mr Abe) - who will now have to deal with some of the most skilful and experienced political operators on the planet: put Trump up against Putin, Erdoğan, or Xi Jinping and I'm pretty sure that we won't have to wait long to see who gets the better of whom.
No one knows what he thinks, if only because he contradicts himself with every breath that he takes. Take his stance on nuclear proliferation, for example, an issue of huge importance to Japan. Last March, the New York Times quoted him as saying that he would be 'open to allowing Japan and South Korea to build their own nuclear arsenals.' Now, using Twitter, which seems to be his favourite medium of communication, he denies ever having said it. 'How dishonest are [the NY Times]. I never said this!'
Another example: on the day before the election, he tweeted that the electoral college, that anachronistic institution which awarded him the presidency even though he won a million fewer votes than Hillary Clinton, was 'a disaster for democracy'. Last Tuesday, again on Twitter, he wrote: 'The electoral college is actually genius.'
A third example: a briefing document drawn up by officials in the Israeli foreign ministry and leaked to Ha'aretz commented laconically: 'The diplomatic process between Israel and the Palestinians will not be a top priority for the Trump administration ... Trump's declarations do not necessarily point to a coherent policy on this issue.'
Trump's supporters say that we commentators have failed to appreciate that what he said during the election campaign should never have been taken literally. He is, after all, a showman, a man who has likened putting together his administration to picking finalists on his TV show. That's another reason that he is so dangerous: quite apart from his terrifying character flaws, he can never be believed. 'Don't take him literally' is another way of saying 'Don't believe a word he says.'
For NATO, the Trump presidency could become a crisis of existential proportions. If (big if) he means anything of what he has said about the alliance, he doesn't really see the point of it. Why should the US come to the defence of allies who have not 'paid their way'? For President Putin, a man with a clear ambition to expand Moscow's influence across its borders, there could be no brighter green light. As for non-NATO US allies like Japan and South Korea, nervously eyeing China's regional ambitions, no wonder Mr Abe was so keen to get a foot in the door.
(I hope, by the way, that someone has reminded Trump that the only occasion when NATO allies have taken joint military action in defence of a fellow-member was after the 9/11 attacks against the US - several NATO countries contributed troops to the invasion of Afghanistan that followed those attacks, and something like 1,500 non-US troops lost their lives.)
Trump has also said (but who knows whether he meant it?) that he wants to renegotiate the Iran nuclear programme deal, and tear up the Paris agreement on climate change. He has no time for the multi-lateral trade agreements on which global trade patterns have depended for the past several decades, and he thinks President Putin has the right ideas in Syria. As Philip Stephens puts it in the Financial Times this morning: 'The president-elect has promised to dissolve the transatlantic security relationship, strike a dirty deal with Russia's Vladimir Putin, and derail the global trading system.'
But who can tell? Perhaps it was all just bluster and he was making it up as he went along. Perhaps he doesn't even remember what he said. In a world of rising tensions and deepening suspicions, whether in the Middle East or east Asia, that kind of uncertainty is deeply troubling.
It is hard to avoid the suspicion that Donald Trump never really expected to end up where he is. So far, he has shown little sign of having given the mundane nitty-gritty of the presidency much serious thought. Apparently, when he finally got round to chatting to Theresa May on the phone the other day, he told her that if she happened to be in the US any time soon, she should definitely get in touch. He clearly neither knows nor cares how such matters are usually handled. On its own, it doesn't much matter, but as an example of his ignorance and lack of preparedness, it matters a great deal.
For the next four years, the world will scarcely dare to breathe as we learn to live with a dangerous and unpredictable president in the White House. His fellow Republicans - indeed, all members of the US Congress, of both parties - bear a huge responsibility, for they, together with the justices of the Supreme Court (until the new president has been able to recast the court to his own advantage) are the only ones who can limit the havoc he wreaks across the globe. Somewhere, someone, I hope, is already starting to work out how they might be able to impeach him before the end of his term. If it were up to me, I would focus on his family and his businesses, whose interlocking interests may well lead him straight towards impeachment territory.
An accidental president is bad enough. An accidental, ignorant, narcissistic president with an alarming propensity to let loose on Twitter late at night is frankly terrifying. But thanks to Mr Trump, and to Ryan Lizza of The New Yorker, I have at least learned a new word this week: kakistocracy. It means 'government by the least qualified or most unprincipled citizens.'
Trust the ancient Greeks to have a word for it ...
Postscript: please don't bother to respond to this by telling me that I'm just a bad loser and that the American people have spoken. As of Thursday morning, Trump had won 61.5million votes and Clinton had won 62.8million. He has no popular mandate and must never be allowed to pretend otherwise.