London won the games on a bid based on a legacy of youth involvement in sport. BT promised to build a broadband legacy for East London and make it a location of choice for the multi-media industries of the future. But the BBC had committed to move to Manchester. The media centre for the 2012 Olympics will therefore be a temporary shed.
That was only the first of the big economies with regard to venues and accommodation that will be needed. Next will come those on transport and security (including cybersecurity) as the fudges unravel, sponsorhip evaporates and the scale of the challenge becomes apparent.
Meanwhile time is running out for rationalising the fragmented empires of the security services and law enforcement, overcoming their legacies of mutual suspicion, creating effective frameworks for co-operation and enlisting and training the army of cybersecurity volunteers that will be needed.