There seems to be a common pattern in a lot of major (expensive, high-risk) initiatives. The politicians seem to have decided they want to do something, and then they cast around for some plausible justification.
But if the first purpose doesn't stick, they don't abandon the scheme. Oh no. They just make up a new purpose.
This pattern seems to apply to the UK Identity Card scheme (discussed in my previous post), as well as to the Iraq war (see my post Yadda Yadda Yadda, discussing the suggestion that the bringing of democracy to Iraq was an imaginary and inauthentic purpose).
The apparent advantage of this pattern is that schemes with imaginary or unstable purpose can never fail - in so far as we can almost always find some purpose or other that has been fulfilled. So there is practically no risk - at least for the politicians who promote these schemes with an enthusiasm that is not always shared by the voters and taxpayers.
However, schemes whose purpose is imaginary or unstable seem to be particularly vulnerable to mission creep and therefore grossly escalating costs. In order to escape one kind of failure (errors of execution), they generate worse kinds of failure (errors of planning, errors of intention).
And eventually the public realises it has been conned. So the politicians get the blame after all. (Or is this just wishful thinking on my part?)