There's a whole bunch of problems with that argument, but probably the biggest is that the US did seem to pretty successfully stop Covid from sucessfully spread

There's a whole bunch of problems with that argument, but probably the biggest is that the US did seem to pretty successfully stop Covid from sucessfully spreading there from anywhere in Asia - pretty much all the outbreaks trace back to Europe via New York, even in parts of the country very far from New York. Also, SARS and MERS did spread to the Western world and most countries did have plans in place to deal with them that informed their early Covid response, especially the UK and US. There's even a really obvious reason why New York and London were hit first that has nothing to do with Trump or Boris - look at when Milan Fashion Week happened and what else was going in that region of Italy, then at the other major fashion centers of the world that'd have lots of travel to Milan that week. It's right slap bang next to the epicenter of Italy's big outbreak which had somehow gone basically undetected, with Italy consistently reporting zero cases a day or two beforehand. Like, the reason populist politicans seem to have played such a disproportionate role in making Covid so bad is because the media ignores any screw-ups that happen in countries run by the kind of boring techocrat they like - I personally have no doubt Italy would've been blamed for dooming the world if Berlusconi or someone like him was in charge.