Japan worried U.S. will eliminate nuclear weapons

Barack Obama wants to see a "world without nuclear weapons". This greatly worries the Japanese:

Before the shift in political power in September, Japan aggressively lobbied a U.S. congressional nuclear task force to maintain the credibility of the U.S. "nuclear umbrella" to deter possible attacks by China and North Korea, sources said Monday.

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Meeting with members of the Congressional Commission on the Strategic Posture of the United States, senior Japanese diplomats expressed deep concerns about the future capability of the U.S. nuclear umbrella, the sources said.

The diplomats also told the commission, which was created by legislation passed during the George W. Bush administration, that the capability to penetrate underground targets with low-yield nuclear devices would strengthen the umbrella's credibility, they said.

Having already suffered nuclear attack the Japanese would prefer no repeats.