Ōe has been involved with pacifist and anti-nuclear campaigns and has written books regarding the atomic bombings of Hiroshima and Nagasaki and the Hibakusha. After meeting prominent anti-nuclear activist Noam Chomsky at a Harvard degree ceremony, Ōe began his correspondence with Chomsky by sending him a copy of his "Okinawa Notes." While also discussing Ōe's "Okinawa Notes", Chomsky's reply included a story from his childhood. Chomsky wrote that when he first heard about the atomic bombing of Hiroshima, he could not bear a celebration for the bombing of Hiroshima, and he went in the woods and sat alone until the evening. Ōe later said in an interview, "I've always respected Chomsky, but I respected him even more after he told me that." Following the 2011 Fukushima nuclear disaster, he urged Prime Minister Yoshihiko Noda to "halt plans to restart nuclear power plants and instead abandon nuclear energy". Ōe has said Japan has an "ethical responsibility" to abandon nuclear power in the aftermath of the Fukushima nuclear disaster, just as it renounced war under its postwar Constitution. He has called for "an immediate end to nuclear power generation and warned that Japan would suffer another nuclear catastrophe if it tries to resume nuclear power plant operations". In 2013, he organized a mass demonstration in Tokyo against nuclear power. Ōe has also criticized moves to amend Article 9 of the Constitution, which forever renounces war.