There was a sense of a nation adrift, not quite sure whether we remained a world power or should throw in our lot with Europe. The referendum earlier that summer produced a Yes vote to stay in the EEC but our enthusiasm has been at best lukewarm ever since. The economy was a mess, with British industry in thrall to union militancy and facing foreign competition that would eventually prove too great to withstand. Harold Wilson was in Number 10 after winning power on the back of a monumental clash between the Tories and the miners that had plunged the nation into periodic darkness. An OPEC embargo and the oil price shock of 1973/74 pushed prices skywards, deepening the gloom. Then along came North Sea oil. Here was our salvation. The infrastructure had been built in one of the most hostile environments imaginable but the rising price of oil that had threatened to bring the country to its knees suddenly made its extraction economically viable. Leave aside the domestic political arguments over the ownership of the oil (“It’s Scotland’s”, said the SNP from the outset) it has been an unalloyed national boon and its exploitation is one of the most important episodes in the post-war history of the UK. Total receipts since the Eighties have amounted to about £300 billion and the industry employs hundreds of thousands of people.