An SNP press release issued after the UK Government published its latest Scotland Analysis paper on borders and citizenship last week yelled:

"Carmichael's scaremongering boomerangs," yelled.

The headline obeyed two basic rules of SNP press releases: i) everything Alistair Carmichael says is "scaremongering", and ii) everything any opponent says must be likened to a flying stick. Apart from that, however, the release rather missed the point. The really striking thing about Whitehall's latest offering was how unscary it was.

Cast your mind back to a dull day in the Commons seven months ago when Pete Wishart and Theresa May were idly goading each other about Scottish independence and British citizenship. Scots would keep their UK passports, insisted the SNP member for Perth and North Perthshire.

Don't be so sure, replied the Home Secretary, advising him darkly to think "very carefully" about what he had said. The inevitable briefings followed, pointing out that the UK could, if it chose, remove UK citizenship and British passports from the citizens of an independent Scotland, and it looked for all the world as if a new scare story was being unleashed on a quivering Scotland. But have a look at last week's Home Office report: "The UK has historically been tolerant of plural nationalities, and therefore it is likely that there would be no barriers to holding both British and independent Scottish citizenships."

True, the Home Office warned that British citizenship could usually only be handed down one generation. But even then the extent of the "threat" distinctly un-terrifying: "Vote Yes and your grandchildren will be Scottish."

It wasn't the only non-scare. The Scottish Secretary said the UK Government had no objection in principle to an independent Scotland joining the common travel area between Britain and Ireland.

The SNP's plans to boost immigration would not be acceptable, Mr Carmichael said, but while his warning had implications for Alex Salmond's long-term economic case it also served to ease fears about border posts at Gretna (which "ultimately could potentially" happen, the Home Office paper said somewhat half-heartedly).

The Scottish Government resisted talk of boomerangs and delivered a more measured response. A spokesman for Fiona Hyslop, the cabinet secretary responsible for external affairs, said it was a "welcome climbdown" from the Home Secretary's implied threats.

Interestingly, the spokesman drew a parallel with the Treasury's announcement last month that it would honour all UK debt in the event of independence, which Alex Salmond also welcomed as a commonsense move in line with the scenario sketched out by his economic advisers. Scottish Government spin doctors - who have always believed the impact of "scaremongering" would diminish over time - are starting to wonder if the UK Government is changing tack. Only time will tell - but even if that is the case it won't please everyone. When our HeraldHolyrood Twitter feed reported that Scots would retain their British citizenship in the event of independence, one committed Nationalist tweeted back: "That sounds like a threat."