It took the CBI nearly five years to realise that befriending the previous Government was not worth the candle. While the employer's body, led then by adair Turner, acquiesced, billions of pounds of extra taxes and regulations were piled on to British business during Labour's first term in office. The CBI woke up to the danger only when Digby Jones became Director-General.  His successor-but-one, John Cridland, looks to have decided to save time by picking a fight with the coalition within months of starting and, in highlighting the vacuum in aviation, rightly identifies the key area where ministers are failing business.  That is not to say that all his battles are worth fighting. In blaming the coalition's drive for more renewables for the closure of Rio Tinto's aluminium smelter in Lynemouth, Northumberland - which will cost 550 jobs - Mr Cridland has picked the wrong fight. aluminium smelting is vastly energy-intensive, and it is no coincidence that the nations best at it, Russia and Canada, have vast and cheap hydroelectric power sources.  With no such supplies available locally, Lynemouth was doomed, just as another former Rio site at anglesey was forced to shut when the nuclear power plant next door to it closed.