After 12 months of watching Donald Trump, it can be difficult to be as shocked by him as we should be. But not after his acceptance speech at the Republican convention in Cleveland. Anyone thinking Mr Trump would use his evening in the national spotlight to reach out to doubters, or to forsake the aggressive scapegoating that won him the nomination, will have been disabused within minutes. For this was an angry, dark, fear-inducing and authoritarian speech straight out of the campaign manual. His message is to make America great again. But his objective is to make America hate again.

Mr Trump spoke for 75 minutes. But what he said at the outset was the core message. That was about growing fear of violence and his unique ability to end it. He claimed America is in crisis, communities in chaos, with attacks on police and terrorism in the cities that threaten America’s way of life. He cherrypicked crime statistics, not mentioning that crime in the US, including murder, is in historic decline, as it is in most democracies. He talked about death and violence, while promising to defend the right to bear the guns that inflict much of it. He said, extraordinarily but characteristically, that violence would end and safety would be restored overnight by the mere act of electing him. Anyone who wanted detail about how he would achieve this instant pacification of America would have been disappointed. But there is never any detail. Mr Trump’s campaign is about him, nothing more.

If there was one especially foul passage, it was the way Mr Trump then laid the blame for his crime wave at the door of illegal immigrants. The elision was deliberate. There were more of them than ever. They were roaming free to threaten peaceful citizens. He told the story of the killing of Sarah Root by an illegal immigrant and then charged that the Obama administration considered her “just one more American life that wasn’t worth protecting; one more child to sacrifice on the altar of open borders”. Plenty of politicians have run as law and order candidates, as Mr Trump said he is doing. But it is hard to think of any other senior politician in any democracy in the modern world who would stoop as low as that.

Mr Trump is not offering an optimistic message, as candidates as different as Franklin Roosevelt and Ronald Reagan always did. No city on a hill for him. No morning in America. Instead, his speech was “all doom, all the time” as the ghost-writer of Mr Trump’s best-selling memoir tweeted. It offered paragraph after paragraph of Hillary Clinton hatred at the climax of a convention in which the main chant has been “lock her up!” and during which Mr Trump’s adviser on veterans, Al Baldasaro, said Mrs Clinton should be shot for treason. His Democratic rival had committed “terrible, terrible crimes”, said Mr Trump. No she hasn’t. She was the cause of “death, destruction, terrorism and weakness”. No she isn’t. Mr Trump is running against a dystopian caricature of his own devising. Mrs Clinton must prove him wrong in Philadelphia next week.

No senior political figure in its modern history has been as willing to repudiate America’s internationalism as Mr Trump. US foreign policy is often misconceived, and worse, but it has, on the whole, contributed to an ordered, open and prosperous world in ways no other country has had the power to achieve. Mr Trump’s “America first” call, echoing the isolationism of the eponymous movement that tried to keep the US out of the war against Hitler, could not have been more designed to unsettle America’s allies. His onslaught against free trade and Nato strategy and costs sends the same message to Europe, and will have Vladimir Putin rubbing his hands.

The trumpeting of “Americanism, not globalism” is destabilising on many levels. It raises economic expectations at home that Mr Trump will be unable to deliver. It helps foment a Manichean view of global problems that require more international commitment not less, like Iran. It comes at a time when global instability takes multiple forms – the conflict in Syria, authoritarian rule in post-coup Turkey, terrorism in France, Russian pressure on Ukraine, Beijing’s unlawful ambitions in the South China Sea, not to mention the impact of the Brexit vote on Europe. Brexit is, nevertheless, a warning. It was a lightning rod for the disaffected. Mr Trump’s campaign also offers overnight answers to inadequately addressed modern anxieties. Mr Trump is in fact part of the problem not the solution. But he is now a step away from being America’s next president.