Bush's USA blocked Russian entry to the World Trade Organisation (WTO), so Putin is now blocking US oil companies from Russian fields.
Igor Shuvalov, a Putin aide, warned in April that the US firms' chances of participating in the undersea drilling project were tied to US support for Russia's WTO bid...
... the Shtokman project is also important to Russia's long-term relations with the US, since most gas from the field is to be shipped to north America in the form of liquefied natural gas. Participation by Chevron or ConocoPhillips could help ease access to the US market.
