(WTO), international agency, successor to the General Agreement on Tariffs and Trade (GATT). Established by a treaty signed in April 1994, concluding the 8-year-long Uruguay Round of international trade negotiations, the WTO began operations on Jan. 1, 1995, with 81 member nations. By January 2007, with the admission of Vietnam after 12 years of negotiation, WTO membership had increased to 150, including the U.S. and nearly all the world's other industrialized nations. A 151st nation, Tonga, had signed an accession agreement in 2005 but deferred membership until July 2007. More than two dozen countries, including the Russian Federation, had applications pending in 2007.

The WTO's mandate is to continue and expand the liberalization of world commerce begun by GATT, eliminating tariffs and other impediments to free trade. Unlike GATT, which dealt principally with tangible goods, the WTO also is responsible for telecommunications, financial and other services, and intellectual property such as books, films, music recordings, and computer software. Members agree to abide by WTO regulations and decisions, but the organization has no enforcement powers. Problems are dealt with by consensus, and a dispute settlement panel has been set up to handle conflicts among members. The principal executive body of the WTO is the General Council. The WTO Secretariat, with headquarters in Geneva, Switzerland, is headed by a director-general.

WTO policy is set by a council of ministers. The first ministerial conference, held in Singapore in December 1996, produced an agreement to reduce tariffs on computers, telecommunications equipment, and other information technology products. Both the second ministerial conference (held in Geneva in May 1998), and the third (in Seattle, Wash., in late 1999), attracted thousands of demonstrators protesting what they alleged was the WTO's inattention to the negative effects of global trade on incomes, labor conditions, and the environment. The large-scale protests in Seattle, some of which turned violent, contributed to the inability of the WTO to settle on an agenda for a new round of trade liberalization.

That task was accomplished by the fourth ministerial conference, held in Doha, Qatar, in November 2001; the conference also approved the admission of China (the world's seventh-leading trading nation) as well as Taiwan. The fifth ministerial conference, held in Cancún, Mexico, in September 2003, ended in acrimony when rich and poor nations were unable to reach consensus on agricultural policy. At the sixth ministerial conference, held in Hong Kong in December 2005, delegates reached agreement in principle on the abolition of agricultural export subsidies by 2013.