Also, per that Lancet letter linked above, Lombardy (where covid first entered Italy) accounts for ⅙ the population of Italy, and as of when the article was written (June 2020, so early on) 53% of the covid deaths.
On the political side, this is something you have to consider. Sure, the US could have just done nothing, but the rest of the world would have been reacting. Imagine the 2020 election, but the Democrats have the legitimate talking point that “Trump did nothing, while every other country on the planet took reasonable measures! Our per capita death rate far exceeds every other country in the world! Trump and the Republicans utterly failed in their duty to protect Americans, and all those deaths are on their heads!”
Don’t forget that without the special treatment Trump gave to the development of the RNA vaccine, there would have no vaccine for a couple years. And @PhillyGuy could not have come to Canada. In fact, my wife and I got our first inoculations in a pharmacy in NYC–and we had to pay for it.
ISTM that Trump was very annoyed that the vaccine wasn’t approved until shortly after the election. Indeed it might have turned the election around. It’s a good thing Kennedy wasn’t around to block the vaccine development.
Depends what you mean by no vaccine.
The BioNTech/Pfizer would have been available in Europe at about the same time without the existence of a country in the middle of North America. But the Moderna did require the U.S. Having one less brand would have delayed worldwide production, to the point of meeting demand, by months, but not years. My recollection was that the Pfizer production volume was a lot more than Moderna.
And there were (still are?) other brands outside the U.S.
If you mean that with another U.S. president the U.S. FDA approval would have taken longer – that’s impossible to know but I doubt it.
P.S. I gather that you could have another perspective because of the vaccine being available in the U.S. before Canada.