The European Union (EU) is a treaty-based, institutional framework that defines and manages economic and political cooperation among its 27 member states (Austria, Belgium, Bulgaria, Cyprus, the Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, and the United Kingdom). The Union is the latest stage in a process of European integration begun after World War II to promote peace and economic prosperity in Europe. This European integration project has evolved over the last decade from encompassing primarily economic sectors to include developing a common foreign policy, an EU defense arm, and closer police and judicial cooperation. The U.S. Congress and successive U.S. administrations have supported the EU project since its inception as a way to foster a stable Europe, democratic states, and strong trading partners. The United States has welcomed EU efforts since the end of the Cold War to expand the political and economic benefits of membership to central and eastern Europe, and supports the EU aspirations of Turkey and the western Balkan states. The United States and the EU share a huge and mutually beneficial economic relationship. Two-way flows of goods, services, and foreign investment now exceed $1.0 trillion on an annual basis, and the total stock of two-way direct investment is over $1.9 trillion. Nevertheless, the U.S.-EU relationship has been challenged in recent years as numerous trade and foreign policy conflicts have emerged. The 2003 crisis over Iraq, which bitterly divided the EU and severely strained U.S.-EU relations, is most notable, but the list of disagreements has been wide and varied. Although Europeans are not monolithic in their views, many EU member states have objected to at least some elements of U.S. policy on issues ranging from the Israeli-Palestinian conflict to U.S. treatment of terrorist detainees to climate change and aircraft subsidies. Since 2003, however, both sides have made efforts to improve relations, and successive U.S.-EU summits have sought to emphasize areas of cooperation and partnership. At the same time, challenges and some tensions remain in the U.S.-EU relationship. U.S.-EU summits are held annually; the 2007 summit took place on April 30 in Washington, DC. President Bush, leading the U.S. side, met with Chancellor Angela Merkel of Germany, the holder of the EU's rotating six-month presidency for the first half of 2007, and European Commission President JosÃ© Manuel Barroso, among others from the EU side. As in previous years, the two sides issued a declaration on political and security issues highlighting areas of U.S.-EU foreign policy cooperation on a wide range of global challenges, from Kosovo to Afghanistan to Darfur. Other summit deliverables were a framework on advancing transatlantic economic integration, the signing of a U.S.-EU air transport agreement, and a joint statement on energy security and climate change. Other selected issues in U.S.-EU relations that figured prominently in summit discussions were the Doha Round of multilateral trade negotiations; the Middle East, including Iran; counterterrorism; and the U.S. visa waiver program. Upon assuming the EU Presidency in January 2007, Germany's Chancellor Angela Merkel proposed a new initiative to enhance and deepen the transatlantic economic relationship. The proposal advocated further liberalizing transatlantic trade and reducing investment barriers by reducing non-tariff and regulatory barriers to trade. The aim of such efforts is to lower costs to businesses on both sides of the Atlantic and to facilitate higher levels of economic growth. Since the establishment of the New Transatlantic Agenda in 1995, a number of initiatives have attempted to remove remaining non-tariff and regulatory barriers to trade. Although each successive initiative has made some progress towards reducing regulatory burdens, both European and U.S. companies heavily engaged in the transatlantic marketplace argue that the results have not proved materially significant. In a departure from these past efforts that relied substantially on voluntary and non-binding dialogues among regulators with political-level endorsement, the Merkel initiative proposed creating an overarching framework to provide greater commitment on the part of political leaders and greater accountability on the part of regulators. According to Business Europe , the EU's main business trade association, this would require legislators and officials to take into account how new laws and regulations affect the transatlantic marketplace. Merkel's proposal also covered issues such as public procurement, intellectual property, energy and the environment, financial markets and security, and innovation. Building on and borrowing from the Merkel initiative, the 2007 U.S.-EU Summit adopted a Framework for Advancing Transatlantic Economic Integration . The framework affirmed the importance of further deepening transatlantic economic integration, particularly through efforts to reduce or harmonize regulatory barriers to international trade and investment. A new institutional structure, a Transatlantic Economic Council (TEC), was established to advance this process. The TEC will be headed on both sides by ministerial-level appointees with cabinet rank. Its mandate is to accelerate on-going efforts to reduce regulatory barriers, in part, by introducing broader participation of stakeholders, including legislators, in the discussions and cooperative meetings. Meeting at least once a year, the TEC will monitor progress and try to identify areas where regulations could be reduced or harmonized. Despite this effort to provide a higher-level political commitment to accelerating transatlantic economic integration, U.S.-European differences in public values over issues such as health safety and environmental protection remain large. The goal of reducing regulatory barriers through harmonization efforts and improved cooperation, combined with divergent regulatory objectives and approaches, thus, remains a difficult target. An aviation agreementâOpen Skies Plusâbetween the United States and EU was signed at the April 30 summit. The agreement, which had been under negotiation for four years, will substantially liberalize the transatlantic air services market. Congressional approval will not be required. The accord will allow U.S. and EU airlines to fly between any city in the EU and any city in the United States with no restrictions on the number of flights, routes, or prices. It also will open to competition London's Heathrow Airport, where landing rights have been restricted to two British and two U.S. carriers. In addition, the agreement provides some enhanced foreign direct investment opportunities in each other's airlines. Open Skies Plus takes effect March 30, 2008, and calls for a second phase of aviation liberalization negotiations to commence by May 30, 2008. The European Commission predicts that the initial agreement will lower airline fares on transatlantic travel, expand the number of passengers over the next five years, and create 80,000 new jobs. But the agreement is not without controversy. Many Europeans argue that it is not balanced because it does not give European carriers the right to fly between U.S. cities and maintains limits on EU ownership of U.S. airlines. Although most U.S. airlines support the agreement, the major U.S. unions representing pilots, machinists, flight attendants, and baggage handlers oppose it on the grounds that it will lead to a further erosion of jobs, benefits, and wages. The World Trade Organization's (WTO) Doha Development Round of multilateral trade negotiations has been suspended since July 2006. The round, which seeks to liberalize world trade flows and provide a boost to development and the world economy, has been stymied by persistent differences among the United States, the EU, and developing countries on major issues such as agriculture and services. Agreement between the EU and U.S. has been key to the conclusion of previous multilateral trade rounds. Accordingly, at the 2007 summit, leaders reaffirmed their "strong desire to reach a prompt agreement ... that is ambitious, balanced, and creates meaningful new trade flows in agriculture, industrial goods, and services among and between the developed and developing countries." Trade negotiators from the two sides, however, face a complicated task of getting the rest of the world to accept any agreement the United States and the EU might reach. Developing countries in particular are much more vociferous in their expectations and demands than they were in previous multilateral trade talks. European leaders have made curbing global climate change an integral objective of EU energy security policy. In March 2007, EU members established binding targets for the use of renewable energy and biofuels and committed to cut greenhouse gas emissions by at least 20% compared to 1990 levels by 2020. Building on this agreement, European officials are reportedly seeking U.S. support for an international treaty regulating greenhouse gas emissions after 2012, when the U.N. Kyoto Protocol is set to expire, and for an international market-based carbon emissions credit trading system. The United States is not party to the Kyoto Protocol, and U.S. officials appear reluctant to commit to global regulation; instead, they advocate transatlantic cooperation to promote alternative and clean energy technology. In light of the differences on global climate change regulation, the United States and EU used the April 2007 summit to launch initiatives jointly promoting technological advances in clean coal and carbon capture and storage, energy efficiency, biofuels, and methane recovery, among other areas. Although European officials agree with the United States that these technologies should help improve transatlantic energy security and mitigate the negative effects of climate change, they are reportedly disappointed by perceived U.S. reluctance to pursue binding international emissions targets and a global carbon trading system. U.S. officials, pointing out that from 2000-2004 carbon dioxide emissions increased at a faster rate in the EU than in the United States, argue that the U.S. approach, based on fostering technological innovation as opposed to binding regulation, is proving more effective in curbing global warming.