Sentence:  The contrast between the Lao and the Vietnamese is an example of how the Annamite Chain has served as a cultural fault line dividing <WSD>Indo-Asia</WSD> and Sino-Asia, as well as a geographic divide. 
Meaning of the word marked with <WSD> tags:  A region comprising parts of Greater Middle East, the Himalayas and Tibet; the countries of the former Indian Union and the sphere of influence of Great Britain.