It was only a matter of time before the ever-rising price of oil became a diplomatic issue. The latest manifestation is plans by Gordon Brown, Britain’s prime minister, to engage with Saudi Arabia and to put oil on the agenda for this weekend’s meeting of the Group of Eight finance ministers. Summitry on the subject makes sense; the question is whether oil-consuming nations have enough leverage to persuade oil exporters to take action.

For Mr Brown, beset by domestic political woes and threatened with protests over high fuel prices, it is convenient to shift the focus to the international oil market. But he is still right to do so. Tax cuts on oil – which are inefficient and likely to be ineffective – are the only domestic policy that could bring down fuel prices in the short term. International deals may have little effect but are unlikely to do any harm.