A fully independent Ukraine emerged only late in the 20th century, after long periods of successive domination by Poland-Lithuania, Russia, and the Union of Soviet Socialist Republics (U.S.S.R.). Ukraine had experienced a brief period of independence in 1918–20, but portions of western Ukraine were ruled by Poland, Romania, and Czechoslovakia in the period between the two World Wars, and Ukraine thereafter became part of the Soviet Union as the Ukrainian Soviet Socialist Republic (S.S.R.).
The country changed its official name to Ukraine, and it helped to found the Common wealth of Independent States (CIS), an association of countries that were formerly republics of the Soviet Union. Ukraine is bordered by Belarus to the north, Russia to the east, the Sea of Azov and the Black Sea to the south, Moldova and Romania to the southwest, and Hungary, Slovakia, and Poland to the west. In the far southeast, Ukraine is separated from Russia by the Kerch Strait, which connects the Sea of Azov to the Black Sea. Ukraine lies in a temperate climatic zone influenced by moderately warm, humid air from the Atlantic Ocean. Winters in the west are considerably milder than those in the east. In summer, on the other hand, the east often experiences higher temperatures than the west. In the 17th century an impressive degree of literacy (for the time) could be found in Ukraine. With Ukraine’s declining political fortunes, however, the rate of popular literacy dropped. By the time of the Russian Revolution of 1917, more than 70 percent of Ukraine’s population was illiterate. The Soviets’ policy of compulsory education helped to wipe out illiteracy in the younger generation, and virtually the entire adult population can now read and write.
Among the specialized scientific facilities available in Ukraine are a number of oceanographic research vessels, based in Odessa and Sevastopol, which support research in the fields of mineral resources, marine biology, and desalinization of seawater. Elsewhere in the country can be found a large cyclotron and one of the finest experimental nuclear reactors in the world, astronomical observatories, and botanical gardens.