Since it flared up last year, the subprime crisis has deeply hurt the American economy from the inside and left the mighty United States in a really bad state. The Federal Reserve has taken heavy measures repeatedly, only to cause severe side-effects instead of removing the root cause of the problem. The Fed's seven interest rate cuts in a roll sent the US dollar into a nosedive, which triggered severe turbulence on the international financial and commodity markets and pushed the global economy to the brink of a major slump.

According to international weighted calculation, the US dollar has depreciated some 25 percent since 2002. The United States, instead of habitually accusing other countries of exchange rate manipulation, should really undertake a thorough checkup of itself.

Because both spot and futures prices of oil are traded in the US dollar on the international market, the depreciation of the US dollar prompted many holders of strong non-US dollar currencies to buy oil futures as well as those who have a lot of US dollar to hedge their losses caused by the dollar depreciation.

The mad dash to exploit or compensate the dollar devaluation has been pushing oil futures price upward. The rotating EU president and the energy minister of Qatar have both warned the oil price could exceed 200 dollars a barrel if the US dollar continues to drop.

Secondly, it has become the main trend for American and European speculative capital to flow under the disguise of avoiding risks.

The power to decide oil prices has been taken over by the oil futures market in New York from the OPEC group since the 1980s as futures trading became synonymous with profiteering. Some studies indicate, however, speculative trading accounted for less than 10 percent of the total trading value of the New York Mercantile Exchange (NYME) before 2003 and did not dictate the long-term trend of oil prices.