Oil prices are up. Barack Obama is to blame. Drilling in the US is the solution. This is the mantra from the president’s opponents. All presidents tend to get the blame for high fuel prices. But with the price of gasoline nearing $4 a gallon, Mr Obama is getting it by the barrel load.

This may be good politics. But it is absurd. Oil, unlike natural gas, is a globally traded commodity, whose price is set in world markets. In 2010, the US produced 7.8m barrels a day, 9 per cent of the world’s supply. Unlike Saudi Arabia, the US lacks spare capacity: it is a price taker. Responding to his critics, Mr Obama said: “We are drilling more. We are producing more. But the fact is, producing more oil at home isn’t enough to bring gas prices down overnight.” These remarks are correct, except for the last word. Producing more oil would have next to no effect on oil prices.

Moreover, if there is a specific cause for the rise in oil prices, it is the tightening of sanctions on Iran, which Republicans support. If, as many desire, military action is taken, the impact on oil prices and the world economy will be far greater.