Is China’s bid for an American oil mini-major just a reasonable business deal or a serious outbreak of energy insecurity in the country set to become the world’s largest economy? In other words, has the final scramble for oil actually started?

“It is a good offer for Unocal, a good offer for America,” said Fu Chengyu, head of China National Offshore Oil Corporation, which last week tried to barge aside an agreed all-American deal by outbidding Chevron for Unocal. But is it too good? There is nothing inherently suspicious about CNOOC bidding $2bn (£1.1bn)more than Chevron; the Chinese company needed to compensate Unocal shareholders for the extra delay involved in the likely US security scrutiny of its bid.