Post ratification referendum?

Can we please put to bed the argument that, if Cameron wants to honour his word, he has to offer the British people a referendum on the Lisbon Treaty, regardless of whether or not it has been ratified?  The left are, understandably, cock-a-hoop that it looks like there will not be a referendum after all.  The smugness is more than a little nauseating, since it is as a result of Labour’s reneging on a manifesto commitment that there was not a referendum in the first place, but there we are.

On the face of it, Cameron’s words were pretty damn conclusive:

Today, I will give this cast-iron guarantee: If I become PM a Conservative government will hold a referendum on any EU treaty that emerges from these negotiations.

Although the next sentence is less so:

No treaty should be ratified without consulting the British people in a referendum.

But the argument put forward by both loons and lefties, that this pledge means that the Tories must either offer a referendum on Lisbon or break his word, is nonsense.  Because there is literally no point in a post-factum referendum on a Treaty that has been enacted.  If the Tories were able to force a referendum before the Czechs ratify the Treaty, then they would be able to withdraw British ratification.  Once Lisbon is ratified by everyone, it is no longer a Treaty, but a part of EU law.  It will not be unpickable, and a British referendum would be nothing more than a glorified opinion poll.

Referendums should be about determining future policy; not for determining what we all thought about the past.