Global Neighbors: A Compendium of International Land and Maritime Borders

The world’s 195+ sovereign states share over 300 land and maritime boundaries. Below is a curated selection of significant bilateral borders, grouped by region, with lengths from authoritative sources (UN, CIA World Factbook, bilateral treaties). Note: Maritime boundaries (EEZ, continental shelf) are often distinct from land borders and subject to ongoing negotiation.

Asia

• Afghanistan–Pakistan: 2,430 km (Durand Line, disputed).
• China–Russia: 4,209 km (world’s 6th longest; fully demarcated 2008).
• India–Pakistan: 3,323 km (Line of Control in Kashmir disputed).
• India–China: 3,488 km (LAC disputed; 1962 war, 2020 clashes).
• Kazakhstan–Russia: 7,644 km (world’s longest continuous land border).
• Saudi Arabia–Yemen: 1,307 km (partially demarcated).

Europe

• France–Brazil: 730 km (via French Guiana—France’s longest border).
• Norway–Russia: 196 km (Arctic; only NATO-Russia land border).
• Spain–UK (Gibraltar): 1.2 km (disputed sovereignty).
• Turkey–Syria: 909 km (complex due to conflict).
• Germany–9 neighbors: Denmark, Poland, Czechia, Austria, Switzerland, France, Luxembourg, Belgium, Netherlands.

Africa

• Egypt–Sudan: 1,273 km (Hala’ib Triangle disputed).
• DRC–9 neighbors: Most borders in Africa (Angola, Zambia, Tanzania, Burundi, Rwanda, Uganda, South Sudan, CAR, Congo).
• South Africa–Lesotho: 909 km (enclave).

Americas

• USA–Canada: 8,891 km (world’s longest; includes 2,475 km Alaska).
• USA–Mexico: 3,145 km (Rio Grande/Río Bravo 2,019 km).
• Brazil–10 neighbors: Every SA country except Chile/Ecuador.
• Chile–Argentina: 5,308 km (Andes; world’s 3rd longest).

Oceania

• Australia–Indonesia: Maritime (Timor Sea, Arafura Sea) — 1997 treaty.
• Australia–Papua New Guinea: 800 km land (Torres Strait) + maritime.

Special Cases

• Enclaves/Exclaves: Baarle-Hertog/Nassau (BE/NL), Kaliningrad (RU), Ceuta/Melilla (ES in MA).
• Condominiums: Pheasant Island (ES/FR, alternates sovereignty 6-monthly).
• Disputed: Kashmir, Western Sahara, South China Sea, Abyei (SD/SS).

This list is illustrative, not exhaustive. For legal/navigational purposes, consult the UN Treaty Series, International Court of Justice records, and national hydrographic offices.