Malaysia itself is
The western part of the Indonesian archipelago and the Malayan peninsula have for at least 1500 years been an important cultural and economic communications centre for Eastern Asia. Trade between India and China was mostly carried on through the Straits of Malacca and the South China Sea. From the earliest times the great cities of the archipelago have lain along this trade route, on the shores of East Sumatra, Western Malaya and North Java. In the pre-colonial and early colonial period, the main centres of wealth and power were Malacca, Banten, Batavia, Djepara, Gresik and Surabaja. Later Medan, Palembang and Singapore came into their own. For centuries there have been constant and extensive migrations between Malaya and Sumatra, Sumatra and Java, Java and Malaya, Java and Borneo. In present day Malaya there are large communities counting Javanese and Sumatran descent. Such migrations were, so far as one can tell, non-political, part of the unrecorded flow of populations all over the world.
Dense jungles and high mountain ranges have meant that the easiest form of communication in the archipelago has been the boat. The calm and shallow Java Sea has for generations been the main link between the islands of Indonesia and the Malay peninsula. Control of the seas has therefore always been the key to empire, both indigenous and European, in this part of South East Asia. Until the 19th century rise of capitalist estate agriculture and mining, the political role of the Dutch, Portuguese and British in the archipelago was not qualitatively different from that of the great Hindu-Buddhist states of Sriwijaya and Modjopahit, and the Islamic kingdoms of Malacca and Atjeh. Rivalries between these coastal powers were the dominating political facts of almost 1,000 years of history, with supremacy shifting from Sriwijaya (8th–10th century), to Modjopahit and its forerunners (12th–15th centuries), Malacca and Banten (16th century), Atjeh, Banten and Batavia (17th century), Batavia (18th century), Batavia and Singapore (19th century), and finally Singapore alone (20th century). The rivalry between Dutch and British imperialism, expressed in the competition between Batavia and Singapore, was in many ways a response to traditional economic and geographic factors. These factors operate to the present day and undoubtedly lie behind the contemporary Indonesian-Malayan confrontation. It is also worth noting that until the 19th century, the political centre of gravity usually lay within the borders of what is now Indonesia, so that the myths of Malay (Indonesian) racial greatness are associated with Java (Modjopahit) and Sumatra (Sriwijaya and Atjeh), rather than with contemporary Malaya.footnote1
The unity of the area is not based simply on geographic and political factors. Most of the important ethnic groups in the area, the Malays, Atjehnese, Javanese, Sundanese, Minangkabao, Buginese and Makassarese
Religion is also a unifying factor. Malaya and Indonesia are the only Islamic countries in the Far East. The degree of ‘real’ Islam of course varies sharply from a largely traditionalist orthodoxy in Malaya, Sumatra and West Java to a subtle mélange of Buddhism, Hinduism and Islam in Central and East Java.