Why South and Southeast Asia Form a Region

South Asia (India, Pakistan, Bangladesh, Nepal, Sri Lanka, Bhutan, Maldives) and Southeast Asia (Myanmar, Thailand, Laos, Cambodia, Vietnam, Malaysia, Singapore, Indonesia, Philippines, Brunei, Timor-Leste) are grouped as a macro-region for compelling reasons:

1. Geographic Proximity & Connectivity

• Land borders: India–Myanmar, India–Bangladesh, China–Myanmar/Laos/Vietnam (linking SE Asia to East Asia).
• Maritime contiguity: Bay of Bengal, Andaman Sea, Strait of Malacca, South China Sea — historic maritime highways.
• Monsoon system: Shared climate driver (SW monsoon June–Sept, NE monsoon Oct–Dec) shaping agriculture, culture, economy.

2. Deep Historical Ties

• Indianization (c. 200 BCE – 1300 CE): Hindu-Buddhist kingdoms (Funan, Champa, Srivijaya, Majapahit, Khmer, Pagan, Ayutthaya) adopted Sanskrit, scripts, law, architecture, statecraft from India.
• Buddhism: Theravada (Sri Lanka → SE Asia), Mahayana (India → China → Vietnam). Shared pilgrimage sites (Bodh Gaya, Sarnath).
• Islam: Spread via Indian Ocean trade (Gujarat, Coromandel → Malacca → archipelago) from 13th century.
• Colonial experience: British (India, Burma, Malaya, Singapore), Dutch (Indonesia), French (Indochina), Portuguese (Goa, Timor) — linked administrative, legal, railway, port systems.

3. Cultural Exchange & Diffusion

• Language families: Austroasiatic (Khmer, Vietnamese, Nicobarese), Dravidian (Tamil in Malaysia/Singapore), Indo-Aryan (Hindi/Urdu diaspora), Tai-Kadai (Thai, Lao, Shan).
• Cuisine: Curry, coconut milk, rice, spices, fermented fish (ngapi, belacan, prahok) — shared palate.
• Arts: Ramayana/ Mahabharata epics (wayang kulit, khon, nang yai), gamelan (Javanese/Balinese), classical dance (Bharatanatyam influence in SE Asia).

4. Economic Interdependence

• ASEAN (1967) + SAARC (1985) + BIMSTEC (1997, bridges both) + RCEP (2020, includes both + East Asia + Aus/NZ).
• India–ASEAN trade >$100B; India–SE Asia investment (pharma, IT, energy, infra).
• Supply chains: Electronics, textiles, auto parts, agri-commodities flow both ways.

5. Geopolitical Convergence (Indo-Pacific)

The "Indo-Pacific" construct (US, Japan, India, Australia, ASEAN) treats South + SE Asia as a strategic continuum — maritime security, supply chain resilience, balancing China. Regional forums (EAS, ARF, IORA) institutionalize this.

6. Emerging Collective Identity

Youth culture (K-pop, Bollywood, streaming), climate vulnerability (cyclones, sea-level rise, Himalayan melt), diaspora networks, digital economy — fostering a sense of shared destiny beyond colonial borders.

South and Southeast Asia aren't just neighbors — they're a civilizational corridor, a trade basin, and increasingly, a strategic unit.