via toru
In the first place, Japan would need to test and re-test its nuclear capabilities. Yes, supercomputers can simulate some of the characteristics of a nuclear explosion, but ultimately Japan would probably have to conduct several tests, over the course of several years, to create a reliable nuclear force.
But how would it deploy such a weapon? On aircraft? Japan has no nuclear-capable aircraft, no bombers or specialized strike aircraft. The country’s Air Self Defense Force does operate several US-designed fighter jets, especially as the F-15, which could conceivably be adapted to carry nuclear weapons. But that would require US permission to open up the plane’s “black boxes” – its electronics and sources codes – in order to nuclearize these aircraft; it is hard to see that happening.
Japan could put its nuclear weapons on missiles. That would require miniaturizing a nuclear weapon to fit on a missile and then developing the missile itself. Japan has a vibrant space-launch industry, but they are the wrong kind of rockets for a nuclear force. A specialized solid-fueled missile would have to be built almost from scratch.
Even then, where would Tokyo put these missiles, whether in silos (which would be vulnerable to earthquakes) or on mobile launchers? Japan is a small and populous country; what region of the country would want to accept these weapons, especially since they would make any such place a high-value target for an enemy first strike? It is likely that many local communities would copy Okinawa in strongly protesting the militarization of their back yards.
Japan could deploy these missiles on submarines, which would require a specialized submarine-launched missile, encapsulated for underwater launch. The country would also have to develop a whole new ballistic-missile submarine (SSBN), most likely nuclear-powered, meaning another technological hurdle (small, extremely safe nuclear reactors) that needs to be overcome.
All this would not be cheap. It cost Britain £15 billion (more than US$19 billion) to create a four-boat fleet of Vanguard-class SSBNs – and London simply bought submarine-launched Trident II missiles off the shelf from the United States (something Washington would likely not do for Tokyo).
・・・・
A nuclear Japan is not unimaginable. At the same time, it is not a thing that could be done on the cheap, in a hurry, or without provoking a massive political tempest.
日本が核武装するには、技術的にもハードル高いわけですね。
スパコンで補える部分もあるが、まず、何度も核実験しないと駄目。F１５に搭載するにしても、核兵器用に整備するには米国の許可がいるが、アメリカは許すまい、と。ロケット技術はあるが固形燃料のミサイル技術はない。核搭載ミサイルの置き場所も見つかるまい、と。潜水艦に搭載するにしても、原子力潜水艦や潜水艦から発射する技術を開発しないと駄目だが、これにはめちゃ金がかかる、と。イギリスは潜水艦発射弾道ミサイルをアメリカから買ったが、アメリカは日本には売ってくれんだろう、と。
核武装した日本というのは想像できないわけではないが、安くすぐにできるというのは無理で、政治的にも大波乱を巻き起こすだろう、と。
ーーーしかし、アメリカは日本に協力する気はないのけ？
イギリスのように同盟国で仲良くしたまま、核武装したほうがアメリカの国益にとっても資すると思うがな。愛人に意地悪して捨てるとろくなことはないんだけどね？
いずれにせよ、日本でも、これからいろんな議論がでてくるでしょうな。
なによりも、
１）中国の拡張主義
２）北朝鮮の軍事的冒険主義 ➕ アメリカを恫喝できる軍事力の獲得
３）アメリカの相対的衰退 ➕ アメリカ国益優先主義
などから、いままでとは異なる大規模な地政学的地殻変動が起きつつあり、日本の安全保障状況が劇的に危うくなっている認識が共有されないとまずいかな、と。
