I completed reading "The Afghan Campaign" by Steven Pressfield.  I admire Pressfield's writing.  But this book began to spook me about a third of the way into the story.  Alexander invaded Afghanistan about 3,000 years ago.  Reading this book was like reading any current account of the fighting taking place today.  I know we are supposed to be all modern and high tech today, but a very great General had the same problems a very long time ago.  It's a great read.  Read it.  Learn a lot.  Read it with a laptop close by hooked up to the internet.  You'll be looking up facts about page 10.  You won't quit looking up stuff until you finish the book.  Don't plan on sleeping once you are half way into the book.  You know who "won" the campaign, but do you know how it was won?