Olivia Waite is a romance author, practicing feminist, and wide-ranging dilettante.
This book starts with a "heads of state making grand decisions" perspective and slowly zooms in as the war approaches -- until there you are outside Sebastopol in the mud and the ruins and surrounded by men dying of exposure and dysentery, while Tolstoy has life-changing revelations on the enemy lines. Perfect for filling in the gaps between the Continental Wars and WWI, especially in regard to Turkey and Russia, which I've often found easy to skip over. I'm trying to be better about that: this book is a great help, and a very substantive read.