David Cameron
A preoccupied David Cameron may have done a good job short term, but long term his decision today maybe harmful. Reuters

The prime minister's decision today to pull Britain to the point of EU departure, may have won a few hearts in the mean time, but the decision to "look after the interests of Britain" may have seriously damaged the UK's long term economy.

David Cameron will head home this evening to hugs and smiles from his back benchers, including the Mayor of London Boris Johnson who said that "the prime minister played a blinder" during the Brussels summit.

There is every possibility that he did. Britain will no longer be involved in with discussions of the euro and that awful headache it has received over the past 18 months, he has safeguarded the City and the financial sector in Britain's interests and he has prevented the UK taxpayer from putting any money into the "firewall" fund.

These are all short term gains for Cameron, and as the euro crisis roles on, he may well be vindicated by all quarters. Again, there is every chance of this happening. Countries, including Ireland, have already made noises of ratifying the treaty via a referendum. Three non-eurozone countries won't sign up to the treaty without parliament support. What is more, there is no guarantee that the measures of this new treaty will work. Again, the detail is lacking from any of the plans, and what could come from this "integrated eurozone" is an undemocratic state where national governments become void.

If this happens, Britain and Cameron will watch from the touchline and be entirely vindicated by their success at this summit.

But as history has taught us countries, most notably Germany, have come back from the brink of economic disaster to absolute stability and growth.

If the eurozone does succeed and the euro succeed with it, there is every chance Britain will be frozen out and "isolated" by the fiscal and monetary policy made by the 26 (and growing) countries of the EU. Britain may be shut out of a magnet of trade and growth, which would put the UK and the prime minister on the back foot. To be a part of the new treaty, could have meant a short term gamble, for a long term gain.

As the political dust settles on the last summit of 2011, a year that began with Greece, Spain and Ireland floundering and Italy on the point of collapse, it has ended with the UK effectively leaving the EU for good.