American–Uzbek relations formally began when the United States recognized the independence of Uzbekistan on December 25, 1991, and opened an embassy in Tashkent in March 1992. U.S.-Uzbekistan relations developed slowly and reached a peak following the U.S. decision to invade Afghanistan following the September 11, 2001 attacks. Relations cooled significantly following the "color revolutions" in the former Soviet republics of Georgia, Ukraine, and Kyrgyzstan in 2003–2005, and the Government of Uzbekistan sought to limit the influence of U.S. and other foreign non-governmental organizations (NGOs) working on civil society, political reform, and human rights inside the country. Relations improved slightly in the latter half of 2007, but the U.S. continues to call for Uzbekistan to meet all of its commitments under the March 2002 Declaration of Strategic Partnership between the two countries. The declaration covers not only security and economic relations but political reform, economic reform, and human rights. Uzbekistan has Central Asia's largest population and is vital to U.S., regional, and international efforts to promote stability and security. According to a 2002 global opinion poll, 85% of Uzbeks view the United States favorably, compared with only 10% who viewed the U.S. negatively. According to the 2012 U.S. Global Leadership Report, 40% of Uzbeks approve of U.S. leadership, with 22% disapproving and 39% uncertain. Bilateral relations Trade and investment Trade relations are regulated by a bilateral trade agreement, which entered into force January 14, 1994. It provides for extension of most-favored-nation trade status between the two countries. The U.S. additionally granted Uzbekistan exemption from many U.S. import tariffs under the Generalized System of Preferences (GSP status) on August 17, 1994. A Bilateral Investment Treaty was signed December 16, 1994; it has been ratified by Uzbekistan and received advice and consent of the U.S. Senate in October 2000. However, the Bilateral Investment Treaty will be unlikely to enter into force until Uzbekistan embarks on economic reform. The government is taking some modest steps to reduce the bureaucratic restraints on the nascent private sector. Assistance The United States' humanitarian and technical assistance to Uzbekistan has decreased markedly since 2004, both as a result of government actions against U.S. implementing partners and U.S. Government restrictions on aid. Since its independence, the U.S. has provided technical support to Uzbekistan's efforts to restructure its economy and to improve its environment, education, and health care system, provided support to nascent NGOs, and provided equipment to improve water