Breaking up is hard to do.
Salmond's first problem is that regardless of the spin put on it by Osborne and friends, it's a policy based on the analysis from the permanent secretary to the Treasury, an independent figure. Salmond can dispute the merit and strength of Sir Nicholas Macpherson's reasoning, but not its source. Instead then he dealt purely with Osborne, only mentioning the paper from the Treasury once. Second, of the two new points he made, his publication of an analysis suggesting a £500m cost to UK businesses if there wasn't a currency union is based on the obvious assumption that, rather than using sterling informally, Scotland sets up an entirely new currency. This would be fair enough if this was the SNP's Plan B, except it clearly isn't. For someone who denounces the negative campaigning and calls out the No campaign as being Project Fear, this is rather desperate stuff, as making the argument has been from the outset. It's also as transparent as can be - if Scotland votes yes, it will use the pound, whether within a currency union or not. No business is going to fall for the same bluster as Salmond has been condemning
On surer ground is the response from Salmond and others to José Manuel Barroso's renewed comments that an independent Scotland joining the EU would "be difficult, if not impossible", if only because Salmond's point that Scotland would almost certainly have an easier time agreeing to join than Cameron will "renegotiating" the rest of the UK's relationship was spot on. This said, we simply don't know how those negotiations will go until they happen, or indeed whether Spain or other states might object, despite suggestions they will keep their own opposition to Catalonian independence as a separate matter. By the same token, Salmond is continuing to bet everything on rUK being more receptive to a currency union once the referendum has been won, as Osborne and pals may well be. Salmond's other argument however, that it is "insulting as well as demeaning" to be told you have no rights to assets built up jointly cuts both ways. He imagines that public opinion in the rUK will side with the newly independent Scotland's claims to the pound, disregarding how bloody-minded and parochial the nationalists south of the border are also. Breaking up is hard to do, as it would be nice for the SNP to acknowledge every now and then.