In 1950, the day after the outbreak of the Korean War, she traveled to the United States together with writer and activist Nogami Yaeko and three other members of the Japan Women's Movement () in order to present US Secretary of State Dean Acheson with a request that a system be created in which Japan could remain neutral and pacifist. Hiratsuka continued to champion women's rights in the postwar era, founding the New Japan Women's Association () in 1963 together with Nogami and noted artist Iwasaki Chihiro, and continuing to write and lecture up until her death in 1971.
On the day after the Korean War began in 1950, Hiratsuka traveled to the United States with Nogami Yaeko and three other members of the Japan Women's Movement. They presented US Secretary of State Dean Acheson with a request for Japan to maintain neutrality and pacifism. After the war, Hiratsuka founded the New Japan Women's Association in 1963 alongside Nogami and Iwasaki Chihiro, continuing her advocacy through writing and lecturing until her death in 1971.