The World Congress of Partisans for Peace in Paris (20 April 1949) repeated the Cominform line that the world was divided between "a non-aggressive Soviet group and a war-minded imperialistic group, headed by the United States government". It established a World Committee of Partisans for Peace, led by a twelve-person Executive Bureau and chaired by Professor Frédéric Joliot-Curie, a Nobel Prize-winning physicist, High Commissioner for Atomic Energy and member of the French Institute. Most of the Executive were Communists. One delegate to the Congress, the Swedish artist , heard no spontaneous contributions or free discussions, only prepared speeches, and described the atmosphere there as "agitated", "aggressive" and "warlike". A speech given at Paris by Paul Robeson—the polyglot lawyer, folksinger, and actor son of a runaway slave—was widely quoted in the American press for stating that African Americans should not and would not fight for the United States in any prospective war against the Soviet Union; following his return, he was subsequently blacklisted and his passport confiscated for years. The Congress was disrupted by the French authorities who refused visas to so many delegates that a simultaneous Congress was held in Prague." Robeson's performance of "The March of the Volunteers" in Prague for the delegation from the incipient People's Republic of China was its earliest formal use as the country's national anthem. Picasso's lithograph, "La Colombe" (The Dove) was chosen as the emblem for the Congress and was subsequently adopted as the symbol of the WPC.