I remain dubious.
Any sales to Argentina would be tracked by the military industrial press.
There have been no sales.
Any actual US military presence would either be top secret, in which case they would not be hauling tanks on the autopista, where anyone could see them,
or it would be publicly announced, and in the papers.
The idea that the USA is attempting to slyly drive M1s around Argentina, and just hoping no one will notice is not believable.
There are a number of people who monitor youtube vids, worldwide, observing the movements and types of weapons used- this would pop up on the internet very quickly.
Even when tanks are transported by train in the USA, vids pop up a few hours later.
plus, an M1070 HET, which is the truck/trailer combo used to transport a 70 ton M1 tank, weighs close to 100,000 kg, with tank. It has 40 wheels.
It is YOOOGE, as a certain orange haired celebrity would say.
It would not be transported without taking up far more than one lane on the autopista, and without lead and follow cars.
Taxi drivers here consider there to be two lanes between the stripes.
The tank itself is 12' wide.
I am singularly unconvinced that the autopista would support such a vehicle without crumbling.
I have seen what crummy 20 ton (fully loaded) argentine trucks do to the roads around here.