Japan warned U.S. over reductions to nuclear arsenal and sought flexible deterrence, 2009 memo reveals

Japan’s dependency on the U.S. nuclear umbrella and the bilateral “nuclear bond” have been strengthened through under-the-table discussions, according to a 2009 Japanese government memo recently obtained by Kyodo News and interviews with officials.

The secret memo, written by strategists nine years ago, demonstrates why the administration of Prime Minister Shinzo Abe gave such high marks to U.S. President Donald Trump’s Nuclear Posture Review, released in February, which emphasized Washington’s commitment to defend its allies, including Japan, in an apparent shift from Obama-era policy.

The memo was presented to the U.S. Congressional Commission on U.S. Strategic Posture, which was composed of 12 nuclear experts and chaired by former Defense Secretary William Perry. A primary purpose of the bipartisan commission was to make concrete proposals to the administration of then-President Barack Obama, which was drafting its own policy review.

“It is difficult for us to specify the weapon systems which the United States should maintain or acquire,” read the February 2009 memo. “But we can list, though not exhaustively, several desired characteristics which the U.S. deterrence capability should have.”

The memo listed six characteristics, including flexible, credible and prompt deterrence capabilities.

“(Washington’s) possible unilateral reduction of its operationally deployed strategic nuclear warheads may have an adverse effect on Japan’s security. When the United States engages in nuclear reduction talks with Russia, China’s nuclear expansion and modernization should always be borne in mind,” the memo said.

In 2009, Obama declared that the U.S. would “seek the peace and security of a world without nuclear weapons.”

The memo was presented to the commission by Vice Foreign Minister Takeo Akiba, then Tokyo’s political representative in Washington.

During a recent interview, a Japanese official involved in drafting the memo said security policy elites like Akiba were so concerned about Obama’s “nuclear-free world” vision that they intensively lobbied influential U.S. experts to reverse course.

Trump’s review was met with praise from Tokyo officials due to its renewed focus on nuclear deterrence to defend the U.S. and its allies.

“Potential adversaries must understand that the United States has the will and response options necessary to deter nuclear attack under any conditions … our deterrence strategy for North Korea makes clear that any North Korean nuclear attack against the United States or its allies and partners is unacceptable and will result in the end of that regime,” the review said.

It also proposes introducing low-yield nuclear warheads for submarine-launched ballistic missiles and sea-launched cruise missiles to boost the credibility of the U.S. nuclear deterrence.

A day after the release of the policy guideline, Foreign Minister Taro Kono said in a statement that, “Japan highly appreciates the latest (review) which clearly articulates the U.S. resolve to ensure the effectiveness of its deterrence and its commitment to providing extended deterrence to (Japan).”

The ministry couldn’t help but issue the statement because the review adopted everything it had wanted, a senior official said.

The memo also emphasized that U.S. deterrence capabilities should be “flexible enough to hold a wide variety of adversary threats at risk.” It raised cyberattacks as onesuch threat.

Also, the concept of introducing low-yield weapons, which was proposed in the latest U.S. review, is one of the items Japanese security experts view as important, according to the Japan memo.

Since 2010, U.S. and Japanese security officials have periodically conducted a series of secret talks on the allies’ deterrence policy through a bilateral framework called “Extended Deterrence Dialogue.”

One of the Japanese participants in the dialogue expressed no surprise with regard to Trump’s policy.

“It’s written(in line with) the consensus of both nuclear communities in Japan and the United States,” said the participant, who was also involved in drafting the 2009 memo.