Contributed by David Carrier / “Miró and the United States,” now up at The Phillips Collection, offers a useful take on an important, much-discussed issue: the origins of Abstract Expressionism. Joan Miró (1893–1983) taught many Americans how to make a successful abstract painting. Between the First and Second World Wars, when American artists were finding themselves, Miró’s work was a welcome and beneficial influence. The Cubist paintings of Braque and Picasso and Matisse’s works from the early twentieth-century may have been greater. But, like Kandinsky, Miró provided…