The Guardian on Saturday led its front page with story headlined Independent Scotland 'may keep pound (29 March).I am hoping that the Scottish National Party's principled opposition to the Trident nuclear WMD system will not be abandoned as part of some murky, unprincipled deal to secure currency union with the pound should Scotland vote to go independent in the referendum in September
But even if some squalid deal were attempted, it would arguably be in breach of the United Kingdom's obligations as a co-drafter of, and with the US and Russia a depositary state for, the 1968 nuclear nonproliferation treaty (NPT).
Article One of the NPT reads: "Each nuclear-weapon State Party to the Treaty undertakes not to transfer to any recipient whatsoever nuclear weapons or other nuclear explosive devices or control over such weapons or explosive devices directly, or indirectly; and not in any way to assist, encourage, or induce any non-nuclear-weapon State to manufacture or otherwise acquire nuclear weapons or other nuclear explosive devices, or control over such weapons or explosive devices." (http://www.un.org/disarmament/WMD/Nuclear/NPTtext.shtml)
Leaving Trident nuclear armed submarines in situ at the Royal Navy dockyard at Faslane on the Clyde would certainly be a an indirect transfer of the nuclear weapons to an (albeit newly formed) nation state recipient. Were Scotland to remain in NATO, it is open to debate how much control through NATO's joint command Edinburgh might have over use of such nuclear WMDs.
When the NPT was negotiated in 1966-7, in papers I uncovered at the National Archives, I found that on 24 January 1967, a joint draft by the US/UK negotiators according to a US embassy aide-memoire, "would ban the transfer of nuclear warheads (as distinct from nuclear delivery vehicles) not only between nuclear weapons states (NWS) and non-nuclear weapons states (NNWS) but also between NWS themselves."
A secret US 'Interpretations memo', dated May 1967, subsequently stated that the NPT would thus prohibit "transfer to any recipient whatsoever 'nuclear weapons' or control over them", meaning bombs and warheads.
So, the depositary states knew exactly what they meant to prohibit under article one of their new treaty. I wonder whether the anonymous minister to whom the Guardian's chief political correspondent spoke has any idea of any of these diplomatic niceties.
But sticking to the international rules are important, as Mr Hague has been stressing to Mr Putin over Crimea and Ukraine over the past few weeks.
Dr David Lowry is the former director, European Proliferation Information Centre (EPIC)