The news that the SNP is preparing to abandon its longstanding opposition to independent Scottish membership of NATO at its national executive meeting this summer has provoked murmurings of discontent, as well as a few loud howls of condemnation. The murmurings emanate from inside the party, with a handful of nationalist MSPs quietly indicating they intend to resist any shift in policy. The howls come from the leaders of the unionist parties, including the Tories' Ruth Davidson and Labour's Jim Murphy, who see the reversal as further evidence of Alex Salmond's failure to get to grips with the defence issue.
As the debate develops, Salmond will justify the move on the grounds it will offer reassurance to those concerned about the capacity of an independent Scotland to meet certain 21st Century security needs. He'll also say that, two decades after the fall of the Berlin Wall, NATO no longer represents the ideological and destabilising force it did during the Cold War.
By contrast, his opponents argue that it will limit the ability of the SNP to achieve one of its central goals: the removal from Scottish waters of British nuclear weapons. They claim that as a member of NATO – a defence alliance built on the principle of nuclear deterrence – Scotland would have an obligation to continue to host the UK's Trident system after having left the Union. They contend further that it is morally and intellectually inconsistent to advocate disarmament while enjoying the "benefits" of a nuclear defence pact underwritten by other countries.
But these criticisms don’t stand up to much scrutiny. Firstly, if other NATO members, like Norway and Germany, can hold non-nuclear status there is no obvious reason why an independent Scotland can't. And secondly, nowhere in NATO's 2010 Strategic Concept agreement does it say that new members are required to develop nuclear weapons capacity, nor that existing members are required to indefinitely maintain those weapons they currently possess. In fact, in committing NATO "to the goal of creating the conditions of a world without nuclear weapons", the preface of the agreement implies the opposite.
However, the real problem for Salmond doesn’t lie with his unionist rivals (who tend to attack pretty much everything he does) or with his own party (which, according to Professor James Mitchell, is already broadly on board). Rather, the danger for the nationalist chief is that in his drive to water down the most radical aspects of his party's programme – and therefore make the break-up of Britain more palatable to "middle-Scotland" – he is alienating left-wing and anti-militarist supporters of independence.
This is significant because, although reluctant to admit it, Salmond knows that victory in the 2014 referendum will depend on the cooperation of small radical groups and progressive civic society organisations, like the Greens and CND. That's not to say the SNP doesn't have the resources or grassroots capacity to run a campaign of its own – clearly it does. But unless it can demonstrate that enthusiasm for full self-government is sufficiently widespread, it will find it much harder to counter the unionist charge that "separatism" is a fringe doctrine fundamentally at odds with Scotland's constitutionally moderate majority.
The first minister has expended considerable energy pandering to the right and its associated business interests in recent years - think of his pledge to cut corporation tax, his embrace of Rupert Murdoch and his monarchism. But he would do well to remember there is a powerful cultural and political left in Scotland, and it’s yet to properly flex its muscles in this debate. His looming u-turn on NATO could be the thing which finally prompts it to do so.