In 1967 Ceausescu's position was further strengthened when he assumed the presidency of the Council of State to become the head of the country in title as well as in fact. Since that time Romania has maintained a firm, orthodox communist control pattern in its domestic affairs but has continued to pursue an independent foreign policy, which has diverged remarkably, from time to time, from those of the Soviet Union and its Warsaw Treaty Organization (Warsaw Pact) allies. Differences have included opposition to the full integration of the Warsaw Pact military alliance, refusal to joint the Soviet bloc in condemning Israel after the 1967 Six-Day Arab-Israeli War, and unilateral establishment of diplomatic relations with the Federal Republic of Germany (West Germany). Perhaps the strongest position vis-à-vis the Soviet Union was taken in 1968, when Ceausescu denounced the so-called Brezhnev Doctrine of limited sovereignty among socialist nations, which was used by the Soviets to justify the invasion of Czechoslovakia (see ch. 10). CHAPTER 3 PHYSICAL ENVIRONMENT AND POPULATION Romania, located in southeastern Europe and usually referred to as one of the Balkan states, shares land borders with Bulgaria, Yugoslavia, Hungary, and the Soviet Union and has a shoreline on the Black Sea (see fig. 1). The interior of the country is a broad plateau almost surrounded by mountains, which, in turn, are surrounded, except in the north, by plains. The mountains are not unduly rugged, and their gentle slopes plus the rolling interior plateau and the arc of lowlands on the country's periphery provide an unusually large percentage of arable land. Romanian historians have remarked that their country's history might have been different had its mountains been located on its borders rather than in the interior. Romania's mountains provided a refuge for indigenous populations but did not constitute barriers against invaders who sought to dominate the area or use it as a crossroad for deeper invasions of the Balkan region (see ch. 2). The prevailing weather is eastern European continental, with hot, clear summers and cold winters. Rainfall is adequate in all sections, and in normal seasons the greater share falls during the summer months when it is of most benefit to vegetation and crops. Soils on the average are fertile. Forests occupy about 27 percent of the land surface. All of the major streams drain eventually into the Danube River and to the Black Sea. The entire length of the Danube in or bordering the country is navigable. There are few canals, and the Prut River is the only other waterway that is navigable for any considerable distance. Several of the rivers originating in the Carpathians have a good potential for hydroelectric power but, because oil and natural gas are abundant, their development has not had high priority.