Everything said about taxes is true, but does not explain why the rate of increase was less in the US during 2 key price increases in that graph. I believe the answer is the US Strategic Oil Reserve. The US Government maintains a huge underground reservoir of crude oil for emergencies such as war so our ships and battle tanks can keep running no matter what. This reserve has ocassionally been tapped during sharp oil price increases to stabilize the US oil market. The oil is only released into the US market, so it provides much more price stability nationally than globally. However, the big oil companies love high oil prices, so there is a certain amount of political pressure not to do this. If the US economy cannot stand the load of higher oil prices, it is more likely that the government will intervene.