A republic in central Asia, bordering on Iran, India and Turkestan. Long divided and ruled by neighboring states, Afghanistan emerged as a unified state in the mid-18th century. During the 19th century, Afghanistan became a battleground in the competition between Russia and Great Britain for influence in Central Asia. During 1881-1919, the country was dominated by the British. Afghanistan regained its autonomy in 1907 and its independence in 1919. In 1973, the monarchy was replaced by a republican government. The republic was overthrown in a pro-Soviet coup in 1978. The new regime was unable to unify the country or to quell conservative resistance in the countryside. In December 1979, the Soviet Union invaded Afghanistan, establishing what it hoped would be a more effective government. The resulting civil war lasted a decade, as U.S.-supported rebels and the Soviet-supported regime fought to a bloody stalemate. During 1989-92, the Soviet Union and the United States withdrew their support, and by mid-1992, the Marxist regime had been ousted, and the various rebel groups began fighting among themselves. One of these groups, the Taliban, gained predominance during 1996 and by 1997 had occupied most of the country. Former seminarians, the Taliban have established a fanatically Islamic regime in Afghanistan. Although Afghanistan began issuing postage stamps in 1871, it did not join the Universal Postal Union until 1928. Until then, Afghani stamps were valid only within the country and required British Indian stamps to be carried abroad.