No.
A full-blown, supervolcano eruption at Yellowstone, ie an 8 on the Volcanic Explosivity Index, would devastate the United States with the immediate ash fall.

Not to worry though, the Volcanic winter which follows would leave every nation on earth scrambling to feed its people. The US would not be a military target for criminal governments to raid to steal food since we wouldn’t have any food left to steal.
If anyone had to worry about governments behaving badly it would be countries south of the equator.
WHY?
Because Yellowstone (and most supervolcanoes) are in the northern hemisphere and, because there tends not to be a whole lot of atmospheric mixing between the northern and southern hemispheres, therefore the southern hemisphere would be less severely affected by the volcanic winter.

Indeed the new superpowers might all be in the southern hemisphere after an eruption of Yellowstone. But in any case no nation on earth would come out undamaged. Full-blown supervolcano eruptions are bad news.
Not the way we are now.
We will be the world’s largest…………hole. We will be the world’s largest dead zone. Mexico will soon be the world’s largest superpower, because we will invade and take over.
Out of necessity we will be coming. Isnt that a twist of fate. Our military will be coming with us, oh yeah and the entire population of our largest state “Canada” will be coming with us. Expect 200 million people (the rest die instantly) to invade Mexico and Central America.
Palestine 🇵🇸 will look like a cakewalk compared to this displacement. All these MAGAs climbing over the wall with their guns, MAGA militias taking over boarder towns, liberals turning into apartheidists since they are not equipped to live off the land (roughing it).
Oh we will still have most of the nukes, and military, the entire navy and Airforce. If 20+ years in the future the Spaceforce will be the greatest fear any potential adversary will encounter.
America has hundreds of military bases around the world. China and damn sure not Russia nor anyone else should stand up to the in the American invasion.
Economically we will be temporarily fucked, but the world’s largest reserves of Gold will come with us. The world will want us back up and running asap, and will help us. Especially Europe, they are essentially a group of States with greater autonomy.
Most of the billionaire and millionaire class will come and quickly reestablished a functioning American style economy. We will finally have centralized healthcare as a hold over from the former Mexican republic. Oh Brazil and Argentina your not safe, your next on the gobble up menu.
Mexico is too small for three populations to fit. Their militaries and gangs will be nothing but a meal to the US Marines and Navy.
I don’t like this scenario but damnit we know it’s true.