I have read this book, twice, and have read the reviews posted on Amazon.com. Only one of them hinted at the substory involving the Ingushi nation of the former Soviet Union. Maybe most of the readers thought that such an ethnic group was fictitious, which it very much is not. Being married to an Ingush, I was most astonished to discover le Carre's accurate representation of the nation's history, something absolutely unattainable in the former Soviet Union where they are systematically maligned. Some of the Ingush warriors and mafia depicted were perhaps a bit seedier than in reality, but the level of authenticity in general was very gratifying, and lent an extra layer of meaning to the book. Yes, there is a love story, certainly, but the real story of the book is the transformation of a citizen of a superpower into a citizen of the world. There is a difference and it does matter.