The future of Trident in the event of a Yes vote

Published: 3 September 2014

As NATO leaders prepare to meet in Wales, Hugh Chalmers of RUSI discusses the future of Trident in the event of a Yes vote.

The increasingly heated tone of the independence debate disguises an important reality: both an independent Scotland and the rest of the UK would have great incentives to work towards a mutually-agreeable and amicable separation. RUSI’s recent research report Relocation, Relocation, Relocation shows that nowhere is this more true than the future of Trident on the Clyde.

If Scotland were to vote for independence in September, both it and the rest of the UK would have great incentives to safely and securely relocate Trident South of the border. However, Holyrood’s aim to remove Trident from an independent Scotland by 2020 would force the rest of the UK into an extremely difficult position and potentially derail any chances of an amicable separation.

Even if a relocation agreement could be finalised by the 2016 target for Scottish independence, this would leave only four years in which to carry it out. If Faslane’s last upgrade took almost a decade to complete, it is unrealistic to expect relocation to be any faster.

An ironic consensus has emerged amongst proponents and opponents of independence that relocating Trident would be impossible, and would force the UK to unilaterally disarm. This need not be the case. There are relocation options available within the rest of the UK; difficult options but options nonetheless. And the political and financial costs of relocation would be tolerable if the rest of the UK remained committed to nuclear weapons.

If this were the case, the rest of the UK would have incentives to relocate as quickly as possible. The ‘ultimate assurance’ of the UK’s national security would become less assuring the more it relied upon Scotland’s continued cooperation. But abruptly kicking Trident out of Scotland could be dangerous in the short term, and would certainly damage Scotland’s position with NATO in the long term.

In the event of a vote for independence, a pledge by the rest of the UK not to prepare Scotland for a successor to the Trident might give Scotland the confidence to accept a more flexible timeline for relocation. Without upgrades to Faslane, the UK would struggle to base a successor submarine in Scotland, and the rest of the UK could not retire its ageing Vanguard submarines until a new base had been developed in its own territory; further incentivising the UK to relocate.

Linking the removal of nuclear forces to the planned transition between nuclear submarines – currently planned for 2028 - would require Scotland to accept nuclear weapons for eight more years than it currently hopes. However, doing so would guarantee that Vanguard will be the last nuclear submarine based on its territory, and would untangle one of the knottiest problems likely to emerge from its independence.

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