Russia's economy is in deep trouble. Crippled by sanctions and stung by slumping oil prices, the nation's currency has lost half its value against the US dollar since June. Because of the volatility of the rouble, many foreign businesses are finding it impossible to operate in Russia and they have either scaled back their operations or actually closed. Russia is a big debtor to foreign banks and to foreign investors and also a major trading partner to Europe, financial risk analyst said. Just this week, technology giant Apple stopped selling its products online into Russia because it could not keep up with the rouble's rapid decline.