If a week is a long time in politics, how long is a poltical lifetime?
Well, now we know the answer to that question – it is approximately three years, according to the DUP.
In October 2006, North Belfast DUP MP Nigel Dodds said that "As far as we are concerned, there will be no devolution of policing and justice for a very long time. I have no evidence whatsoever to suggest that that is likely to happen within a political lifetime."
And yesterday DUP leader Peter Robinson said that 'he will promote to unionists the devolution of justice powers if the financial aspects can be perfected'.
Three years ago Dodds said that policing and justice powers would not be passed to the Northern Ireland Assembly within two years of the restoration of devolution and that 'it would take longer for unionists to trust Sinn Fein to take responsibility for security'.
But yesterday Robinson said that "I believe that the structures that we've put in place are sufficient to command that confidence and I want to do the same with the financial arrangements".
So, in DUP mathematics, three years is a political lifetime. That flexibility helps to explain a lot of other things, of course, such as Edwin Poots belief that the earth is a mere 6,000 years old. In DUP mathematics that may mean that it is really 60,000 years old. Still wrong, of course, but maybe the DUP use a logarithmic scale?