The European Nations left South East Asia during the 19th century.
The reasons include the presence of indigenous religions, western education, and the effect of socialism and communism.
<u> Explanation:</u>
European nations such as Portugal, Spain, Netherlands, Great Britain, and France had colonies in South East Asia. During the 1500s and 1600s, Europeans were able to gain power over South East Asia through trade and commerce.
The southeast Asian countries achieved nationalism through various approaches. The Buddhist and Islamic supporters of Burma and Indonesia respectively initiated national movements.
In Burma, new western-educated elite joined hands with Buddhist Monks and with other Burmese people.
In the Philippines, western-educated leaders fought against Spain. In Malaya, educated Malays were motivated into Civil service.
Meanwhile in Indonesia, the people who were educated from Dutch schools formed the P.N.I - Indonesian Nationalist Party. Communist and socialist activities played a massive role in Indonesia, Vietnam, etc.
I’m not entirely sure what is being asked here, but the Tigris and Euphrates rivers is the only place in Egypt (besides the nile delta) with non-arid ground. That’s why most people live around there:
