In May 1940, Linus Pauling received a letter from Nobel laureate Harold Urey. Urey had sent Pauling a form letter explaining William Allen White's position and asking Pauling to collect signatures in support of the CDAAA cause. Pauling found himself torn. As much as he believed in peaceful, rational resolution, he felt there was little chance of the United States avoiding combat. Nevertheless, the idea of committing American soldiers to the war, as advocated by the FFF, was unsettling to him. He supported the ideals of the CDAAA but his coming actions would suggest he believed war to be an inevitability.

Despite the immediacy of the violence in Europe, Pauling was also finding hope for the future in a new movement spearheaded by Clarence Streit, an Atlanticist and major proponent of the CDAAA. In 1939 Streit published Union Now in response to the ineffectiveness of the League of Nations. In his text, he argued that western democracies should form an international governing body. By creating a unified democracy, he claimed, participating nations would be protected both economically and militarily, and be in an improved position to affect global change over time. He believed that a powerful union of democracies would eventually spread democratic ideals to other nations, preventing movements like Nazism.

Undeterred by a scathing response from philosophers and writers like George Orwell, Ava Helen Pauling became deeply interested in Streit's work, even dedicating a scrapbook to newspaper clippings and pamphlets related to the movement. Linus was soon convinced by his wife's enthusiasm and the couple became charter members of the Pasadena Chapter of Federal Union, Inc., a non-profit organization supporting Streit's ideas. In a 1940 letter to Arthur Hill and his wife, Pauling wrote that he and Ava Helen were "working on the Union Now plan for combining with the British democracies and on the Committee for the Defense of America by Aiding the Allies."

For the first time in his life, Pauling felt the interest and desire to engage in the political arena. On April 8, 1940, he gave a speech discussing the need for a unification of democracies. Encouraged by his receptive audience, he delivered several more talks during the summer and fall, including one on science and democracy at Caltech. The Paulings' political work would only go so far, though. With a war growing in Europe and U.S. isolationism beginning to wane, world government was of little concern to most politicians and private citizens. Before long, even Pauling himself would be forced to put aside his political ideals in the face of more immediate concerns.