Further to my piece here on Cameron's isolation, it has to be said, to be fair, that it was a tough call for Cameron to join in the Euro ship at this point. Since the inception of the Euro as a single currency, everyone has been pointing out that a single currency only works if there is a single fiscal regime governing taxation and spending policies in all the participants. Commentators have pointed out that by being apart from the euro, we have ways of sorting out our financial problems which include the possibility of devaluing our currency, something that is not available to Ireland and Greece.
What Merkozy have been trying to do is to stop the euro horse, take it out of its harness, turn it round and re-couple it to the cart this time the right way round so that it is pulling the fiscal cart, not trying to push it. If you see what I mean.
For Cameron to have signed up with the 27 would still not have committed him to the Euro itself. He would be there with 10 others also not in the Euro - but at least he would have been in there. By staying out, he was giving a signal of no confidence in the Euro project. To have joined would have sent a confidence signal at a time when the markets are looking for exactly that.
The euro plunged in value after the euro summit, and some if not all of that plunge is down to Cameron's decision, because it signified that there is serious non-unanimity in the EU.
This may be seen as possibly the first ever case of a rat refusing to board a sinking ship. OK. But the fact remains that the rat is sitting in a small tender irrevocably tied to the good ship Euro, and if the ship goes down, it is going to drag the tender, complete with rat, down with it.
So it may have been a tough call, but by refusing to join up, for spurious City of London reasons, Cameron has chosen to be part of the problem, not part of the solution.