Tensions arose from colonial borders, rival territorial claims, historical animosities, national interests, the Cold War and resources. Most disputes combined several causes.
Colonial rule left unclear or disputed borders. The claims to Preah Vihear and Sabah both rested on agreements made in the colonial era.
Historical animosities shaped how states saw each other. Thailand and Cambodia had a long history of rivalry. Singapore and Malaysia separated in 1965 after bitter political quarrels.
New states pursued national interests and prestige. Sukarno wanted Indonesia to lead the region, and the Philippines wanted to assert itself in Asian affairs.
The Cold War added suspicion. Indonesia's confrontation of Malaysia drew in Britain, the USA and the USSR. Vietnam's invasion of Cambodia in 1978, covered in the Third Indochina War chapter, split the region along Cold War lines.
Resources also mattered. Singapore depended on water from Johor, which made supply a sensitive issue between the two countries.
- Colonial legacy
- Disputed borders and agreements.
- Historical animosity
- Thai-Khmer rivalry; the Singapore-Malaysia split.
- Cold War
- Konfrontasi; the Third Indochina War.
Worked example: Sorting the causes
How can you organise the causes of tensions?
- Territory: Preah Vihear, Sabah, northern Borneo.
- History: Thai-Khmer rivalry; the split between Singapore and Malaysia.
- Interests and ideology: Sukarno's ambitions; the Cold War.
- Resources: water from Johor.
Watch out for this
Each dispute had a single cause.
Most disputes combined causes. Konfrontasi involved territory, ideology, Sukarno's ambitions and the Cold War.
Check your understanding
Which dispute was mainly about a resource?
- The Singapore-Malaysia water dispute
- Preah Vihear
- Sabah