Read the book, visit the country. Whatever you do, read.

My nominee for Albania.

Only two out of 22 for me: Belgium and Colombia. However, 173 countries aren't mentioned. It's impossible to summarize any country in just one book, but Henry Miller did a decent job of it with The Colossus of Maroussi, even if he was American, not Greek.

The moral of the story: read.

22 Ambassadors Recommend the One Book to Read Before Visiting Their Country (Conde Nast Traveler)

Preparing for a visit to a foreign country can often be overwhelming, with no shortage of things to learn before you go. Where should you eat? Where should you stay? What do you tip? More so than this service information, though, is a sense of cultural understanding that's hard to put your finger on. With this in mind, language learning app Babbel asked foreign ambassadors to the U.S. to pick the book they believe first-time visitors to their country should read before they arrive. Their answers may surprise you. Note: "H.E." stands for His or Her Excellency, the official title for ambassadors to the U.S.

Belgium
“War and Turpentine is a book about three generations of Belgians, focusing on the legacy of WWI and Belgium’s exceptional painters. Long-listed for the 2017 Man Booker Prize, War and Turpentine is the absolute companion book for any art and history lover traveling to Belgium.” —H.E. Dirk Wouters

Colombia
H.E. Juan Carlos Pinzón recommends 1967's One Hundred Years of Solitude by Gabriel García Márquez, which tells the multi-generational story of the Buendía family.