1. Indonesia (1,904,569 km2)
Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania, between the Indian and Pacific oceans. It consists of more than seventeen thousand islands, including Sumatra, Java, Borneo (Kalimantan), Sulawesi, and New Guinea (Papua). Indonesia is the world's largest island country and the 14th largest country by land area, at 1,904,569 square kilometres (735,358 square miles). With over 273 million people, it is the world's 4th most populous country as well as the most populous Muslim-majority country. Java, the world's most populous island, is home to more than half of the country's population.
The sovereign state is a presidential, constitutional republic with an elected legislature. It has 34 provinces, of which five have special status. The country's capital, Jakarta, is the second-most populous urban area in the world. The country shares land borders with Papua New Guinea, East Timor, and the eastern part of Malaysia. Other neighbouring countries include Singapore, Vietnam, the Philippines, Australia, Palau, and India's Andaman and Nicobar Islands. Despite its large population and densely populated regions, Indonesia has vast areas of wilderness that support one of the world's highest levels of biodiversity.
The Indonesian archipelago has been a valuable region for trade since at least the 7th century when Srivijaya and later Majapahit traded with entities from mainland China and the Indian subcontinent. Local rulers gradually absorbed foreign influences from the early centuries and Hindu and Buddhist kingdoms flourished. Sunni traders and Sufi scholars brought Islam, while Europeans introduced Christianity through colonisation. Although sometimes interrupted by the Portuguese, French and British, the Dutch were the foremost colonial power for much of their 350-year presence in the archipelago. The concept of "Indonesia" as a nation-state emerged in the early 20th century and the country proclaimed its independence in 1945. However, it was not until 1949 that the Dutch recognised Indonesia's sovereignty following an armed and diplomatic conflict between the two.
Indonesia consists of hundreds of distinct native ethnic and linguistic groups, with the largest one being the Javanese. A shared identity has developed with the motto "Bhinneka Tunggal Ika" ("Unity in Diversity" literally, "many, yet one"), defined by a national language, ethnic diversity, religious pluralism within a Muslim-majority population, and a history of colonialism and rebellion against it. The economy of Indonesia is the world's 16th largest by nominal GDP and 7th by GDP at PPP. The country is a member of several multilateral organisations, including the United Nations, World Trade Organization, International Monetary Fund, G20, and a founding member of Non-Aligned Movement, Association of Southeast Asian Nations, Asia-Pacific Economic Cooperation, East Asia Summit, Asian Infrastructure Investment Bank, and Organisation of Islamic Cooperation.
2. Myanmar (676,578 km2)
Myanmar, officially the Republic of the Union of Myanmar, is a country in Southeast Asia. Myanmar is bordered by Bangladesh and India to its northwest, China to its northeast, Laos and Thailand to its east and southeast, and the Andaman Sea and the Bay of Bengal to its south and southwest. With a size of 676,578 square kilometres (261,228 square miles), Myanmar is the largest of the Mainland Southeast Asian states by area. As of 2020, the population is about 54 million. Its capital city is Naypyidaw, and its largest city is Yangon (Rangoon). Myanmar has been a member of the Association of Southeast Asian Nations (ASEAN) since 1997.
Early civilisations in Myanmar included the Tibeto-Burman-speaking Pyu city-states in Upper Burma and the Mon kingdoms in Lower Burma. In the 9th century, the Bamar people entered the upper Irrawaddy valley and, following the establishment of the Pagan Kingdom in the 1050s, the Burmese language, culture and Theravada Buddhism slowly became dominant in the country. The Pagan Kingdom fell due to the Mongol invasions and several warring states emerged. In the 16th century, reunified by the Taungoo dynasty, the country was for a brief period the largest empire in the history of Mainland Southeast Asia. The early 19th-century Konbaung dynasty ruled over an area that included modern Myanmar and briefly controlled Manipur and Assam as well. The British East India Company seized control of the administration of Myanmar after three Anglo-Burmese Wars in the 19th century and the country became a British colony. Myanmar was granted independence in 1948, as a democratic nation. Following a coup d'état in 1962, it became a military dictatorship under the Burma Socialist Programme Party.
For most of its independent years, the country has been engrossed in rampant ethnic strife and its myriad ethnic groups have been involved in one of the world's longest-running ongoing civil wars. During this time, the United Nations and several other organisations have reported consistent and systematic human rights violations in the country. In 2011, the military junta was officially dissolved following a 2010 general election, and a nominally civilian government was installed. This, along with the release of Aung San Suu Kyi and political prisoners, has improved the country's human rights record and foreign relations, and has led to the easing of trade and other economic sanctions. There is, however, continuing criticism of the government's treatment of ethnic minorities, its response to the ethnic insurgency, and religious clashes. In the landmark 2015 election, Aung San Suu Kyi's party won a majority in both houses. However, the Burmese military remains a powerful force in politics.
Myanmar is a member of the East Asia Summit, Non-Aligned Movement, ASEAN and BIMSTEC, but not a member of the Commonwealth of Nations. It is a country rich in jade and gems, oil, natural gas and other mineral resources. Myanmar is also endowed with renewable energy; it has the highest solar power potential compared to other countries of the Great Mekong Subregion. In 2013, its GDP (nominal) stood at US$56.7 billion and its GDP (PPP) at US$221.5 billion. The income gap in Myanmar is among the widest in the world, as a large proportion of the economy is controlled by supporters of the former military government. As of 2016, Myanmar ranks 145 out of 188 countries in human development, according to the Human Development Index.
3. Thailand (513,120 km2)
Thailand, officially the Kingdom of Thailand and formerly known as Siam, is a country in Southeast Asia. Located at the centre of the Indochinese Peninsula, it is composed of 76 provinces, and covers an area of 513,120 square kilometres (198,120 sq mi), and a population of over 69 million people. Thailand is the world's 50th-largest country by land area, and the 20th-most-populous country in the world. The capital and largest city is Bangkok, a special administrative area. Thailand is bordered to the north by Myanmar and Laos, to the east by Laos and Cambodia, to the south by the Gulf of Thailand and Malaysia, and to the west by the Andaman Sea and the southern extremity of Myanmar. Its maritime boundaries include Vietnam in the Gulf of Thailand to the southeast, and Indonesia and India on the Andaman Sea to the southwest. Nominally, Thailand is a constitutional monarchy and parliamentary democracy; however, in recent history, its government has experienced multiple coups and periods of military dictatorships.
Tai peoples migrated from southwestern China to mainland Southeast Asia from the 11th century; the oldest known mention of their presence in the region by the exonym Siamese dates to the 12th century. Various Indianised kingdoms such as the Mon kingdoms, Khmer Empire and Malay states ruled the region, competing with Thai states such as the Kingdoms of Ngoenyang, Sukhothai, Lan Na and Ayutthaya, which rivalled each other. Documented European contact began in 1511 with a Portuguese diplomatic mission to Ayutthaya, which became a regional power by the end of the 15th century. Ayutthaya reached its peak during cosmopolitan Narai's reign (1656–1688), gradually declining thereafter until being ultimately destroyed in the 1767 Burmese–Siamese War. Taksin (r. 1767–1782) quickly reunified the fragmented territory and established the short-lived Thonburi Kingdom. He was succeeded in 1782 by Buddha Yodfa Chulaloke (r. 1782–1809), the first monarch of the current Chakri dynasty.
Through the 18th and 19th centuries, Siam faced imperialist pressure from France and the United Kingdom, including many unequal treaties with Western powers and forced concessions of territory; it nevertheless remained the only Southeast Asian country to avoid direct Western rule. Siamese system of government was centralized and transformed into modern unitary absolute monarchy in the reign of Chulalongkorn (r. 1868–1910). Siam joined World War I siding with the allies, a political decision to amend the unequal treaties. Following a bloodless revolution in 1932, Siam became a constitutional monarchy and changed its official name to "Thailand". Thailand was a satellite of Japan in World War II. In the late 1950s, a military coup under Field Marshal Sarit Thanarat revived the monarchy's historically influential role in politics. Thailand became a major ally of the United States, and played a key anti-communist role in the region as a member of the Southeast Asia Treaty Organization (SEATO). Apart from a brief period of parliamentary democracy in the mid-1970s, Thailand has periodically alternated between democracy and military rule. Since the 2000s, Thailand has been caught in a bitter political conflict between supporters and opponents of Thaksin Shinawatra, which culminated in two coups, most recently in 2014 and the establishment of its current and 20th constitution.
Thailand is a founding member of the Association of Southeast Asian Nations (ASEAN) and remains a major ally of the United States. Despite comparatively sporadic changes in leadership, it is considered a regional power in Southeast Asia and a middle power in global affairs. With a high level of human development, the second-largest economy in Southeast Asia, and the 20th-largest by PPP, Thailand is classified as a newly industrialized economy; manufacturing, agriculture, and tourism are leading sectors of the economy.
4. Vietnam (331,212 km2)
Vietnam, officially the Socialist Republic of Vietnam, is a country in Southeast Asia and the easternmost country on the Indochinese Peninsula. With an estimated 97.3 million inhabitants as of 2020, it is the 15th most populous country in the world. Vietnam shares its land borders with China to the north, and Laos and Cambodia to the west. It shares its maritime borders with Thailand through the Gulf of Thailand, and the Philippines, Indonesia and Malaysia through the South China Sea. Its capital city is Hanoi, while its most populous city and commercial hub is Ho Chi Minh City, also known by its former name of Saigon.
Archaeological excavations indicate that Vietnam was inhabited as early as the Paleolithic age. The ancient Vietnamese nation, which was centered on the Red River valley and nearby coastal areas, was annexed by China in the 2nd century BC, which subsequently made Vietnam a division of China for over a millennium. The first independent monarchy emerged in the 10th century AD. This paved the way for successive imperial dynasties as the nation expanded geographically southward until the Indochina Peninsula was colonised by the French in the mid-19th century. Modern Vietnam was born upon the Proclamation of Independence from France in 1945. Following Vietnamese victory against the French in the First Indochina War, which ended in 1954, the nation was divided into two rival states: communist North and anti-communist South. Conflicts intensified in the Vietnam War, which saw extensive US intervention in support of South Vietnam and ended with North Vietnamese victory in 1975.
After North and South Vietnam were reunified as a communist state under a unitary socialist government in 1976, the country became economically and politically isolated until 1986, when the Communist Party initiated a series of economic and political reforms that facilitated Vietnamese integration into world politics and the global economy. As a result of the successful reforms, Vietnam has enjoyed a high GDP growth rate, consistently ranked among the fastest-growing countries in the world. It nevertheless faces challenges including poverty, corruption, inadequate social welfare and a poor human rights record, including increasing persecution of religious groups and human rights advocates and intensifying restrictions on civil liberties. By 2010, Vietnam had established diplomatic relations with 178 countries. It is a member of such international organisations as the United Nations (UN), the Association of Southeast Asian Nations (ASEAN), the Asia-Pacific Economic Cooperation (APEC) forum, and the World Trade Organization (WTO).
5. Malaysia (330,803 km2)
Malaysia is a country in Southeast Asia. The federal constitutional monarchy consists of thirteen states and three federal territories, separated by the South China Sea into two regions, Peninsular Malaysia and Borneo's East Malaysia. Peninsular Malaysia shares a land and maritime border with Thailand and maritime borders with Singapore, Vietnam, and Indonesia. East Malaysia shares land and maritime borders with Brunei and Indonesia and a maritime border with the Philippines and Vietnam. Kuala Lumpur is the national capital and largest city while Putrajaya is the seat of the federal government. With a population of over 32 million, Malaysia is the world's 45th-most populous country. The southernmost point of continental Eurasia is in Tanjung Piai. In the tropics, Malaysia is one of 17 megadiverse countries, home to a number of endemic species.
Malaysia has its origins in the Malay kingdoms which, from the 18th century, became subject to the British Empire, along with the British Straits Settlements protectorate. Peninsular Malaysia was unified as the Malayan Union in 1946. Malaya was restructured as the Federation of Malaya in 1948 and achieved independence on 31 August 1957. Malaya united with North Borneo, Sarawak, and Singapore on 16 September 1963 to become Malaysia. In 1965, Singapore was expelled from the federation.
The country is multi-ethnic and multi-cultural. About half the population is ethnically Malay, with large minorities of Chinese, Indians, and indigenous peoples. While recognising Islam as the country's established religion, the constitution grants freedom of religion to non-Muslims. The government is closely modelled on the Westminster parliamentary system and the legal system is based on common law. The head of state is an elected monarch, known as Yang di-Pertuan Agong, chosen from the hereditary rulers of the nine Malay states every five years. The head of government is the Prime Minister.
After independence, the Malaysian GDP grew at an average of 6.5% per annum for almost 50 years. The economy has traditionally been fuelled by its natural resources but is expanding in the sectors of science, tourism, commerce and medical tourism. Malaysia has a newly industrialised market economy, ranked third-largest in Southeast Asia and 33rd-largest in the world. It is a founding member of ASEAN, EAS, OIC and a member of APEC, the Commonwealth and the Non-Aligned Movement.