I was not intending to comment on the anniversary of the referendum, but there is one aspect of it which I feel should not be forgotten.
Opinion polling immediately before the referendum showed that there was a reasonable chance of Yes winning, albeit by a narrow margin. There are three possible explanations for the difference between the polls and the referendum result; perhaps all three are valid to some degree. The first is that the opinion polls were overestimating the Yes vote. I suspect this is what the Unionists would argue – in this scenario, the Vow was, with hindsight, unnecessary and this somehow diminishes, in their eyes, the need to honour it. The second explanation, which some independence supporters seem to accept, is that significant numbers of people who had intended to vote Yes succumbed at the last minute to the threats of Project Fear. The third is that the Vow tipped the balance in favour of No by seducing many of those whose first preference would have been Devo Max, but would have preferred independence to the status quo.
If I remember correctly, in a poll carried out for Lord Ashcroft immediately after the referendum, 26% of No voters (about 14% of all those who voted) gave the prospect of additional powers being granted to the Scottish Parliament following a No vote as a reason for their choice. Before the infamous Vow, just days before the referendum, there was little if any reason to believe that Westminster would reward Scotland for a No vote with significant additional powers for the Scottish Parliament. It therefore appears that about a quarter of No voters may have been influenced significantly by the Vow; if even two fifths of these people would have voted Yes had there been no Vow, then Yes would have won.
I suspect that there are very few people in Scotland, other than dyed-in-the-wool Unionists, who believe that the Vow has been, or will be, honoured. With the Vow, the Unionists offered a deal to the Scottish electorate, Devo Max or something close to it in return for a No vote. However, as soon as they got the result they wanted – quite possibly only because of the Vow – they reneged on it. In my view, that is sufficient reason to regard the No vote as invalid and to demand a new referendum – sooner rather than later.