A visiting U.S. analyst said Japan's continued insistence on reliance on the U.S. nuclear umbrella was a major obstacle to any effort to reduce the number of nuclear weapons in the world.

Gregory Kulacki, a senior analyst with the Union of Concerned Scientists, criticized at a news conference in Tokyo on April 25 the position taken by the Japanese government early in the first term of U.S. President Barack Obama calling for maintenance of the U.S. nuclear deterrent.

A few months later in April 2009, Obama would speak in Prague on seeking a world free of nuclear weapons.

Kulacki touched upon a hearing by the Congressional Commission on the Strategic Posture of the United States in February 2009 at which a number of Japanese officials, including Takeo Akiba, then a minister with the Japanese Embassy in Washington, presented the Japanese position. Akiba now serves as vice foreign minister.

According to Kulacki, the Japanese officials distributed a document related to the U.S. nuclear umbrella that said the "U.S.'s deterrence capabilities should be flexible, credible, prompt, discriminating and selective, stealthy and demonstrable, and sufficient to dissuade others from expanding or modernizing their nuclear capabilities."

Kulacki added that the exchange between the panel and Japanese officials led to the establishment of a panel on extended deterrence that included high-ranking officials from Japan and the United States working on foreign policy and defense.

Moreover, Kulacki said that Japan has not changed its position on nuclear deterrence, which led to the high praise expressed by Foreign Minister Taro Kono when the Trump administration announced it would seek to expand the role of nuclear weapons when it released its nuclear posture review this year.

Kulacki said that such moves have made his task much more difficult for trying to promote dialogue between the United States and China on nuclear arms control.

"Japan is the single biggest obstacle for my job," he said.

Regarding the explanation given by the Japanese officials to the congressional commission, Seiji Osaka of the opposition Constitutional Democratic Party of Japan submitted a set of questions to the government asking its position on the matter.

The Cabinet of Prime Minister Shinzo Abe on April 10 approved a response that said the explanations given by the officials had been approved by then Foreign Minister Hirofumi Nakasone and represented the position of the government.

Nakasone submitted a written response to The Asahi Shimbun about his approval that said he had nothing to add to what was included in the Cabinet response. He added that while he believed the matter was handled appropriately within the Foreign Ministry and with the prime minister's office, he could not recall the details of what transpired.