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South-Eastern Asia
A mainland peninsula and 25,000 islands between two oceans
South-Eastern Asia splits neatly in two: a mainland peninsula — Myanmar, Thailand, Laos, Cambodia, Vietnam, and peninsular Malaysia — and a maritime scatter of tens of thousands of islands making up Indonesia, the Philippines, Brunei, Singapore, East Malaysia, and Timor-Leste. Eleven countries, about 697 million people, and a position on the sea lanes between the Indian and Pacific oceans that has made it a crossroads for two thousand years. Indonesia alone, with 285 million people spread over some 17,000 islands, is the fourth-most-populous country on earth and holds the largest Muslim population anywhere.
The mainland is corrugated by mountain ranges running north to south, with the great rivers — the Irrawaddy, the Chao Phraya, and above all the Mekong, which passes through six countries — carving fertile valleys and enormous rice deltas between them. Hkakabo Razi in northern Myanmar, at about 5,881 meters, is the highest point. The maritime half sits astride the Ring of Fire: Indonesia has more active volcanoes than any other country, and the eruptions of Tambora in 1815 and Krakatoa in 1883 were heard around the world. Rainforest, coral reef, and monsoon rain define the whole region, and the Coral Triangle here holds the richest marine biodiversity on the planet.
Indian and Chinese influence arrived early and layered over local kingdoms, leaving Angkor, Borobudur, and Bagan behind; Islam came with traders, Christianity with the Spanish in the Philippines, and colonial rule with almost everyone else — Thailand alone was never colonized. The twentieth century brought Japanese occupation, independence wars, and the Vietnam War with its still-lethal legacy of unexploded ordnance. ASEAN, founded in 1967, now binds ten of the eleven states into a bloc of real economic weight, with Singapore among the richest countries on earth and Myanmar, in civil war since the 2021 coup, among the most troubled. The South China Sea, claimed almost entirely by Beijing, is contested by four members at once.