A painting in light tones by Janice Biala forms the prelude. Born in 1903 in Poland, which was then part of Russia, she emigrated to the USA with her family in 1913. In 1952 she painted the picture that is now displayed so prominently in the Museum Barberini in Potsdam.

Her name is not among those mentioned in connection with post-war American art. Neither does that of Hedda Sterne, whose dark-colored painting “N.Y.

The start is program. With the exhibition entitled “The Form of Freedom”, curator Daniel Zamani wants to present “International Abstraction after 1945”, from Europe and North America, and wants to tread well-trodden paths and leave them at the same time. Coming in by presenting works by all the artists famous as abstract artists, such as Mark Rothko, Willem de Kooning or Barnett Newman, but leaving at the same time by adding the overlooked to the list of 52 participating artists. Most of them are female artists, of whom only a few, like Lee Krasner or Helen Frankenthaler, have achieved the same visibility in the art world.

And the opening with Janice Biala makes a second thing clear: the close connection that exists between old Europe and the young continent on the other side of the Atlantic in the development of abstraction. Europe, in this case France, responded to the horrors of the dictators and, not to forget, their collaborators with existentialism as a philosophy of radical, if tragic, freedom. In the transatlantic exchange, the USA relied on artists who had already fought for their freedom, in many cases, especially among immigrants of Jewish origin, through liberation from oppression and persecution. For them, for the emigrants and hence immigrants, the promise of freedom had come true. Also for those who did not have to flee persecution, like Willem de Kooning, who entered the country illegally in 1926, remained without a passport for decades and nevertheless rose to world fame.

In 1948 the first Venice Biennale took place after the war, with only 15 participating nations – but the collector Peggy Guggenheim, who used one of the empty pavilions and showed works by Pollock, whom she unwaveringly promoted, as well as works by those who were also still unknown in Europe Rothko, Clyfford Still, and Robert Motherwell.

The European scene took notice: there was something new, something radical; and although Peggy Guggenheim, who later transferred her New York-built collection to Venice, had never hidden the roots of US abstraction in European surrealism, the Americans were perceived as wholly distinct.

Pollock became the central figure. Tragically surrounded by his psychological problems and constant excesses, he presented the excitement and risk of freedom in a prototypical manner. His “Drip Paintings” had thrown off the eggshells of Surrealism and had become pure “Action Painting”, in which the execution of the act of painting and its result on the canvas became one. Pollock lived “in” his paintings. And they have been exhibited around the world, with strong participation from the Museum of Modern Art and the US Information Service.

Thank goodness the Barberini exhibition does not promote hero worship. Instead, Pollock’s partner, Lee Krasner, has an equal say and, as can be seen from a direct comparison of the images, is of the same stature. In addition to “Action Painting”, the exhibition gives due space to color field painting, so that the contemplative images of Rothko or Newman unfold; particularly beautiful is Newman’s picture pair “Adam – Eva” from 1950-52, in which the contrasting division into brown and red creates an enormous tension.

The fine color nuances in Helen Frankenthaler’s “Blue Bellows” from 1976 are similar. The year indicates that the curator Zamani does not stop at the post-war period, but draws a bow to the end of the 20th century. In between are the late 1950s and early 1960s when US abstraction was indeed at the forefront, reinforced by appearances at documenta 2 in 1959 and 3 in 1964. Morris Louis was added and most notably the celebrated Sam Francis, from whom Barberini -Founder Hasso Plattner owns the luminous, wall-filling late work “My Shell Angel” from 1986, which was one of the reasons for this exhibition.

And Europe? In 1958, Will Grohmann, who was already an important art critic in the Weimar period, wrestled the judgment that one could “speak of an American school in view of the large number of high talents” – and saw “the fortress of the French school shaken”. First France, then all of Europe, responded with the “Art informel”, as the catchy phrase went. The difference in the formats remains striking: the Europeans initially painted small, intimate pictures, such as the unfortunate Wols, who later achieved fame as a German emigrant in Paris. Three pictures of him, who took refuge from the Nazis, and three of his soul mate Jean Fautrier, who fought in the Résistance, form such a heavyweight on a single wall area of ​​the exhibition that many a large American format pales in comparison.

Finally, curator Zamani gives the German informal a well-deserved tribute. Karl Otto Götz, Ernst Wilhelm Nay, Fritz Winter, Fred Thieler, Bernard Schultze, they were all scarred by the war and understood “informal”, abstract and gestural painting as liberation from their traumatic experiences. Winfred Gaul, one of the youngest members of the Flakhelfer generation, summed up the moral issue by asking, “Painting! (…) Isn’t that madness, after everything that has happened?”

The “madness” was prolific on both sides of the Atlantic and remained so for decades. The “abstraction as a world language” that the “documenta” makers proclaimed in 1959 was not the only language of its time, but it was an incredibly powerful and polyphonic one. It was and is a language that left national narrow-mindedness behind like no art movement before it. And in which artists spoke equally. The impressive proof of this long-denied fact is probably the greatest achievement of the exhibition in the Museum Barberini.