via mozu
To former Defense Minister Shigeru Ishiba, the time has come to discuss letting the U.S. military bring nuclear weapons within the country's borders. "Is it right to say that Japan will not host them but will take shelter under the American umbrella?" the veteran lawmaker in the ruling Liberal Democratic Party asked in a television appearance Wednesday.
The proposal speaks to concern that the nuclear umbrella might not work as advertised. With North Korea having developed an intercontinental ballistic missile that can reach the U.S. and working on a miniaturized warhead to go with it, Washington could think twice about responding in kind to a nuclear attack on Japan for fear of retaliation, the thinking goes. Ishiba and peers worry that if Pyongyang realizes this, the American pledge to defend Japan with nuclear force could lose credibility and thus its power as a deterrent.
Enabling the U.S. military to bring a portion of its nuclear capabilities to Japan -- by letting nuclear-missile-equipped submarines call on bases here, for example -- could make Pyongyang more reluctant to move against Japan. And unlike during the Cold War, when the U.S. deployed many tactical nuclear weapons in West Germany, the arms could be kept in Japan only temporarily, blunting public opposition.
自民党の石破茂元防衛相は６日のテレビ朝日番組で「米国の傘で守ってもらうといいながら、日本国内に置かないという議論は正しいのか」と述べた。米軍の核兵器の日本への持ち込みについて議論を始めるべきだとの見解を示した。
北朝鮮は核兵器の小型化や米本土に届く大陸間弾道ミサイル（ＩＣＢＭ）を開発し、米国内でも脅威論が強まる。米国が核兵器による自国への報復を恐れ、北朝鮮が日本を核攻撃しても反撃しないのでは――。石破氏が危惧するのは米国の核の傘が機能せず、抑止力が弱まる状況だ。
そこで石破氏が議論を呼びかけたのが米軍の核持ち込みだ。たとえば核ミサイルを搭載した米原子力潜水艦が日本の基地に寄港できるようになれば、北朝鮮は日本に手出ししにくくなるとみる。冷戦下の米国が旧ソ連に対抗するため多くの戦術核を旧西ドイツに配備したのと異なり、一時的な寄港なら国民の理解も得やすい可能性もある。
