The US has always been an indispensable ally. That could be changing – not because America’s friends want it to change, but because President Donald Trump does not value alliances. Co-operation with others does not suit his "America First" mindset. What a pity. As a teenager in Scotland, I had American friends, sons and daughters of officers at a US Air Force base. One friend’s mother made us a snack, a sandwich that lives in my memory. It was enormous. The sandwiches at my Scottish home had cheese or meat but this American sandwich was four centimetres thick, stuffed with chicken, cheese, tomatoes and pickles – simply wonderful. That was the beginning of my love for America. As children, we learned that the US Air Force was part of Nato defending us against communism, and that together with our European allies we were stronger. There was so much to admire. American businesses, music, movies, writers all seemed to lead the world. American people were among the friendliest I met anywhere. The western US – Wyoming, Arizona and the likes – really did have cowboys on horses. And it is still true. From Bill Gates and Jeff Bezos to Google and Facebook, many of America’s greatest entrepreneurs, musicians, movie directors and novelists are world beaters. But the America I fell in love with years ago <a href="https://www.thenational.ae/world/europe/europe-must-no-longer-rely-on-us-for-protection-merkel-1.729306">seems destined to avoid leading the world</a> in any of the great battles that affect us all. The US still has the most powerful military machine, but does anyone look to American leadership to solve the biggest of our problems? The global pandemic? Climate change? Providing an example of good health care for all Americans? Good governance? Even if you disagreed with specific policies or foreign military interventions, America always tried to be – in former president Ronald Reagan’s striking phrase – a “shining city on a hill". But now? Viewing Mr Trump’s daily news conferences, the shining city on a hill looks and sounds more like grumpy, eccentric muttering to himself behind a wall. The <a href="https://www.thenational.ae/world/trump-says-china-could-face-consequences-over-pandemic-1.1007668">US row with China</a> is the most obvious example. There are good reasons to discuss with Beijing a better way to manage trade, revitalise the world economy and other multilateral relationships. But instead of cool-headed (and quite boring) discussions, this has now evolved – at least as far as the White House is concerned – into <a href="https://www.thenational.ae/world/the-americas/as-coronavirus-spreads-china-and-us-engage-in-a-blame-game-1.993556">a blame game about coronavirus and the biggest economic slowdown of our lives</a>. Every country is learning lessons in dealing with the disease. Perhaps America's superb scientists will be first with a vaccine. But Mr Trump has taken his dislike of China and multilateral international institutions to new levels by <a href="https://www.thenational.ae/world/the-americas/trump-s-who-funding-decision-causes-alarm-around-the-world-1.1006135">cutting US funding for the World Health Organisation</a>. The WHO now joins the United Nations, the European Union and <a href="https://www.thenational.ae/opinion/comment/trump-s-stubborn-self-belief-may-actualise-putin-s-dream-to-destroy-nato-1.747424">even Nato</a> as an organisation that he clearly finds tiresome. In historical terms, this is like a rerun of the worst of 1920s American isolationism. It did not end well. After helping create the League of Nations, the US refused to join, pursuing an "America First" policy that only truly ended when Japan bombed the US Pacific Fleet at Pearl Harbour. Now in 2020, the person whose office once proudly boasted of the President of the United States being "the leader of the free world" <a href="https://www.thenational.ae/opinion/comment/coronavirus-why-donald-trump-should-think-like-a-global-leader-1.992387">may be offering some kind of leadership</a> – but the world is not following. It is no surprise that a popular US board game is called <em>Fortress America</em>, in which North America fights against the world. It is a strangely negative mindset for the world's strongest military power. With Mr Trump attacking state governments run by Democrats, we are in for a nasty presidential election at the same time as scientists fear Covid-19 will be a disaster for poorer countries. It is thought likely to mutate and hit the rich world again in a second wave, perhaps this autumn. <a href="https://www.thenational.ae/world/the-americas/who-defends-itself-following-criticism-from-us-president-donald-trump-1.1003634">That is why international co-operation and the WHO is so necessary.</a> That is why if American leadership fades and Mr Trump takes away American dollars, the vacuum could be filled by the very country Mr Trump is trying to punish, China. In difficult times, most of us need friends. Mr Trump seems to need enemies. And listening to his daily news conferences, berating journalists for asking necessary questions, offering answers that America’s scientific experts then patiently correct, it made me think of an American crooner from the past, Jim Reeves. He once sang: “Make the world go away / Get it off my shoulder / Say the things we used to say / And make the world, make it go away.” But the world will not go away. The global economic shock and coronavirus will not go away. And much of the world would like to have our indispensable ally back. In November, American voters can show that their country's influence does not have to decline just because <a href="https://www.thenational.ae/opinion/trump-s-bungling-of-coronavirus-will-reshape-us-politics-1.994820">its current leader is out of his depth</a>. But for now, an American president on the brink of an economic slump who did not take coronavirus seriously at first and who still does not take climate change seriously is not a leader. He is a liability. <em>Gavin Esler is a journalist, author and presenter</em>