I was introduced to this book through a Fresh Air Interview on NPR with the author. The Tenth Parallel refers to the line of latitude dividing Christianity and Islam in several African and Southeast Asian countries. The book examines the political, social, and economic clashes along this line between the two major religions.
To me the most interesting part of the book was Griswold's account of accompanying Franklin Graham, son of the Rev. Billy Graham and founder of the humanitarian relief organization Samaritan's Purse, on a visit to Sudan to meet with President Omar al-Bashir. According to Griswold, Graham was, unfortunately, seen as a representative for all of America and Christianity. Graham and Bashir (who is Muslim) spent most of their time trying to convert the other to their own religion. Another interesting aspect of the book explored the role of influential Christians in the formation of US foreign policy, which has been perceived as using US global prominence as an extended evangelistic took. Some may debate the validity of that, but it is worth considering.
The other valuable aspect of the book is exploring Muslim societies in Africa and Asia rather than the Middle East. This helps paint Islam as a global religion and not exclusive to a few ME countries, especially Indonesia--the most populous Islamic country. I appreciated the author maintaining an unbiased opinion in reporting on the two religions and she does a commendable job of showing the positives (social justice and humanitarian work) and negatives (religious/politically fueled killing and wars) initiated by Christianity and Islam.
The overall impression I left with from the book is that the conflict between the two religions in Sudan, Nigeria, Ethiopia, Indonesia, Malaysia, and the Philippines is more driven by political and economic issues rather than religious disagreements. That may or may not be true.
For a much better introduction to the book than this review, visit NPR's website with the interview. I'll admit this isn't the most interesting book I've read and can be historically dense at times, it is certainly relevant and helpful to gain a proper global understanding of the two religions.