You know in the past month I've eaten at a couple of one-stars that people here would claim were graded on the American curve...except they were in Europe. And that's not the first time that's happened.
I'm fully prepared to believe that European three-star > American three star. and maybe the same for twos. I'm not at all sure that's true of one's....Michelin seems to give a star to any restaurant that meets a certain service, décor, price and precision/chef-iness level. no matter where it's located.