I've been towing for many years trailer between 1 and 1.5 tons across the Alps with max 2 liter engines. Currently, my car (Saab 9-3 1.9l twin turbo diesel automatic drive) gives me 44 mpg with a 1 ton trailer and develops about 400 Nm torque - plenty enough for any situation. It is rated for 1.6 tons. With my 1 ton trailer, I don't exceed 120 kph because I don't trust the trailor tires above that speed. It's got decent brakes, too :-)
BTW, one of the criterions for trailor mass ratings is that the car must be able to start from a full stop on a 12% slope.

Having driven a lot in the US, the main difference between US and Europe cars are how the suspensions are set. A typical US-built mid-size car would be rated "crap" in Europe, and I would never think of attaching my favorite toy to it. In such a situation, I do understand the thinking of US drivers to go for big mass and big engines - what else can you do if there is no engineering?