Central Asia is the core region of the Asian continent and stretches from the Caspian Sea in the west to China in the east and from Afghanistan in the south to Russia in the north. It is also sometimes referred to as Middle Asia, and, colloquially, “the ‘stans” (as the six countries generally considered to be within the region all have names ending with the Persian suffix “-stan”, meaning “land of”) and is within the scope of the wider Eurasian continent. The region, along with Russia, is also part of ‘the great pivot’ as per the Heartland Theory of Halford Mackinder, which says that the power which controls the Central Asia –richly endowed with natural resources– shall ultimately be the Empire of the world. In modern contexts, all definitions of Central Asia include these five republics of the former Soviet Union: Kazakhstan (pop. 16 million), Kyrgyzstan (3.8 million), Tajikistan (6.0 million), Turkmenistan (4.2 million), and Uzbekistan (28.2 million), for a total population of 57.1 million as of 2013-2014. Afghanistan (pop. 31.1 million) is also sometimes included. Various definitions of its exact composition exist, and not one definition is universally accepted. Despite this uncertainty in defining borders, it does have some important overall characteristics. For one, Central Asia has historically been closely tied to its nomadic peoples and the Silk Road. As a result, it has acted as a crossroads for the movement of people, goods, and ideas between Europe, Western Asia, South Asia, and East Asia. During pre-Islamic and early Islamic times, Central Asia was a predominantly Iranian region that included the sedentary Eastern Iranian – speaking Bactrians, Sogdians and Chorasmians, and the semi-nomadic Scythians and Alans. The ancient sedentary population played an important role in the history of Central Asia. After expansion by Turkic peoples, Central Asia also became the homeland for many Turkic peoples, including the Kazakhs, Uzbeks, Turkmen, Kyrgyz, Uyghurs and other extinct Turkic nations. Central Asia is sometimes referred to as Turkestan. Since the earliest of times, Central Asia has been a crossroads between different civilizations. The silk route which passed through Central Asia connected Muslim lands with the people of Europe, India, and China. This crossroads position has intensified the conflict between what Andrew Phillips and Paul James call continuing formations of tribalism and traditionalism and intensifying processes of modernization. They argue that: From the mid 19th century, up to the end of the 20th century, most of Central Asia was part of the Russian Empire and later the Soviet Union, both being Slavic majority countries. As of 2011, the 5 “stans” are still home to about 7 million Russians and 500,000 Ukrainians.