Thousands of islands and a long arm of land called the Malay Peninsula make up Southeast Asia. Myanmar, Thailand, Laos, Cambodia, and Vietnam lie entirely on the mainland. These countries have highland areas and lowland river valleys with fertile soil. Myanmar has a socialist government established by military leaders. Laos, Cambodia, and Vietnam are all poor countries that have been affected by recent conflicts.

The island countries of Southeast Asia are Indonesia, Malaysia, Singapore, Brunei, and the Philippines. Indonesia is an archipelago of more than 13,600 islands, and is the world's fourth most populous country. It also has a strong economy based on large reserves of oil and natural gas, many mineral resources, and agriculture. Islam is the major religion. Malaysia is rich in mineral resources and is a major producer of palm oil and rubber. Its capital, Kuala Lumpur, is a commercial center. The city of Singapore has one of the world's busiest harbors. Because of their productive trade economy, the people of Singapore enjoy a high standard of living. Brunei has rich deposits of oil and natural gas. Brunei's ruler, or sultan, makes all economic and political decisions. The Philippines, an archipelago of more than 7,000 islands, is the only Christian country in Southeast Asia.