Fascinating, I wonder if anyone has told the Japanese?
The shadow defence secretary, Emily Thornberry, later confirmed that the idea would be considered as part of the defence review, launched on Friday. Thornberry said it was the “Japanese option” to maintain submarines and nuclear capabilities without actually having operational nuclear weapons......
Thornberry told the BBC’s Sunday Politics: “The way that it works is that the Japanese have got a capability to build a nuclear bomb...[but] you can then put them on to, or you can use them, in various delivery forms. So that’s a possibility, that is an option.” She said she would not speculate on what the review would recommend but she added that Corbyn “said there’s a number of options, and I said the Japanese already have this as the way that they use theirs”.
Japan's non-nuclear weapons policy
Japan's non-nuclear weapons policy is a policy popularly articulated as the Three Non-Nuclear Principles of non-possession,
non-production, and non-introduction of nuclear weapons.........
Pacifism bill: Why Japan won't build a nuclear weapon quickly
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But it should be noted that under the terms of the Non-Proliferation Treaty -- which Japan ratified in 1976 -- states are entitled to peaceful nuclear technology for energy purposes if they forswear nuclear weapons.
To ensure that the country's nuclear sites remain exclusively for peaceful use, they are subjected to intensive scrutiny by the International Atomic Energy Agency in Vienna. The Agency consistently verifies the accuracy and completeness of Japan's declarations regarding its nuclear facilities, material, and activities and conducts monitoring and inspections at relevant facilities. Its role in Japan will continue to be particularly important in order to dispel any fears that the country may harbor nuclear weapons intentions.
China and the International Atomic Energy Agency are not the only ones following Japan's nuclear activity closely. Two other audiences are noteworthy. The first is Japan's public, who have become increasingly wary of the risks and dangers associated with nuclear technology -- whether for civilian or military applications -- following the disaster at Fukushima in 2011. The second is the country's closest ally, the United States, who is similarly attentive to the state of Japan's nuclear program.
This is ignoring the point of a SSBN force permanently at sea in the first place, to prevent decapitation and to respond to a first strike. Or is Corbyn expecting a letter? In the event that such a farcical policy was introduced, the first indication of any intent to deploy would itself be a major escalatory issue, inviting the very strike it is purported to prevent.