Soviet Union, Mongolia followed a somewhat similar path. Often acting as the unofficial sixteenth Soviet republic, it shed the communist system only in 1996, but quickly ran into economic problems. See: History of independent Mongolia. The economic performance of the region since independence has been mixed. It contains some of the largest reserves of natural resources in the world, but there are important difficulties in transporting them. Since it lies farther from the ocean than anywhere else in the world, and its southern borders lay closed for decades, the main trade routes and pipelines run through Russia. As a result, Russia still exerts more influence over the region than in any other former Soviet republics. Nevertheless, the rising energy importance of the Caspian Sea entails a great involvement in the region by the US. The former Soviet republics of the Caucasus now have their own US Special Envoy and inter-agency working groups. Former US Secretary of Energy Bill Richardson had claimed that "the Caspian region will hopefully save us [the US] from total dependence on Middle East oil". Some analysts, such as Myers Jaffe and Robert A. Manning, estimate however that US' entry into the region (with initiatives such as the US-favored Baku-Tbilisi-Ceyhan pipeline) as a major actor may complicate Moscow's chances of making a decisive break with its past economic mistakes and geopolitical excesses in Central Asia. They also regard as a myth the assertion that Caspian oil and gas will be a cheaper and more secure alternative to supplies from the Persian Gulf. Despite these reservations and fears, since the late 1980s, Azerbaijan, Kazakhstan, and Turkmenistan have gradually moved to centre stage in the global energy markets and are now regarded as key factors of the international energy security. Azerbaijan and Kazakhstan in particular have succeeded in attracting massive foreign investment to their oil and gas sectors. According to Gawdat Bahgat, the investment flow suggests that the geological potential of the Caspian region as a major source of oil and gas is not in doubt. Russia and Kazakhstan started a closer energy co-operation in 1998, which was further consolidated in May 2002, when Presidents Vladimir Putin and Nursultan Nazarbayev signed a protocol dividing three gas fields – Kurmangazy, Tsentralnoye, and Khvalynskoye – on an equal basis. Following the ratification of bilateral treaties, Russia, Kazakhstan and Azerbaijan declared that the northern Caspian was open for business and investment as