What was the author's purpose in writing Three Cups of Tea?
Greg Mortenson wrote Three Cups of Tea to show his experiences in trying to further education in poverty-stricken regions. After being rescued from K2 by the Korphe village, he promised to build a school there, and ran into opposition both from religious extremists who threatened his life, and from people who thought his cause was hopeless. Instead, Mortenson insisted that the only way to improve the lives of common people in poor areas is education, especially for women.
"...we've launched 114 Tomahawk cruise missiles into Afghanistan so far. Now take the cost of one of those missiles... which I think is about $840,000. For that much money, you could build dozens of schools..."
(Mortenson, Three Cups of Tea, Google Books)
The point is that by providing education for the people living in poor areas, and especially those controlled by the Taliban and similar religious extremists, it is possible to change the minds of the people instead of cowing them with military force. Generations of people are brought up to believe the words of their leaders without question; education will promote the ability to question authority without fear. Women, who tend to remain in their home villages (as opposed to men who leave) are the most important target of education, since they will pass their knowledge on instead of taking it away.