Since 2004, Washington and New Delhi have been pursuing a "strategic partnership" that is based on shared values and generally convergent geopolitical interests. Numerous economic, security, and global initiatives – including plans for civilian nuclear cooperation – are underway. This latter initiative, first launched in 2005, reversed three decades of American non-proliferation policy. Also in 2005, the United States and India signed a ten-year defence framework agreement, with the goal of expanding bilateral security cooperation. The two countries engaged in numerous and unprecedented combined military exercises, and major US arms sales to India were concluded. An Open Skies Agreement was signed in April 2005, enhancing trade, tourism, and business via the increased number of flights, and Air India purchased 68 US Boeing aircraft at a cost of $8 billion. The United States and India also signed a bilateral Agreement on Science and Technology Cooperation in 2005. After Hurricane Katrina, India donated $5 million to the American Red Cross and sent two planeloads of relief supplies and materials to help. Then, on 1 March 2006, President Bush made another diplomatic visit to further expand relations between India and the U.S.