Live Aid co-founder Sir Bob Geldof has called on young people to "be calm and think" and turn away from Donald Trump and other modern populist leaders, who he called the "commanders of the armies of stupidity".
In an outspoken attack on world leaders, from Russian President Vladimir Putin to Mr Trump, Sir Bob spoke of a "great retreat from reason" as he addressed delegates at the opening of the 2016 Summit of One Young World.
Speaking in Ottawa, the Boomtown Rats singer told the young audience: "We must not succumb to the fools." He was critical of British foreign secretary Boris Johnson and other architects of the United Kingdom's "Brexit" from the European Union but reserved particular contempt for Republican Presidential candidate Mr Trump, talking of how "a liar, fool, and a racist vomits his bile onto the disinherited of the United States".
Sir Bob, a One Young World Counsellor, identified a crisis in confidence in the great institutions of the world. "Who believes now in the European Union when it is mired in repeated crises and seems incapable of reviving itself? Who now believes in the authority of the UN as the slaughter of Aleppo continues right now?"
Taking the stage after an optimistic address from the Canadian Prime Minister, Justin Trudeau, Sir Bob conceded that he could be seen as a "grumpy uncle" and took a bleak view of how the world is being run. "I believe we are in some terrible moment, some great retreat from the ability to at least influence the direction of world travel," he said. "Everything seems so complex, nothing seems to work. And the politicians, leaders, and experts are not to be trusted or believed."
He complained that the "horror" of World War Two had been reduced to "mere history".
In a reference to One Young World's spectacular Opening Ceremony in which delegates representing more than 190 countries carried their national flags in a display of international unity, Sir Bob noted that some of the countries represented were run by despotic regimes. "How many of those places are mired in terrible brutality?" he asked. "How many of us cheered those flags over which some over-bearing thug currently rules?"
Attacking populist leaders, he called on the audience to not be "gulled" by "the commanders of the armies of stupidity" and to turn away from the "puerile simplicity" of their political rhetoric. "It is logic and reason and all that difficult stuff that allows us to be at our most human," he said: "The future is not binary, that false choice of dystopia or utopia."
Sir Bob concluded with an apology to the young audience of around 1300 delegates on behalf of his contemporaries. "We old men have betrayed two generations - our parents' and yours. We squandered and lost the generous past they gave us and we passed on, at best, a fragile future."