Symbolism, Imagery, Allegory
The central event in the book is the capital city of Russia being occupied, looted, then totally burned to the ground – and then rebuilt anew from the ashes. Now, don't get us wrong – this was a real event that happened pretty much how Tolstoy describes it. Still, it is a pretty vibrant image of rebirth, especially since it happens as a plot counterpoint to the way the main characters shed their old lives and find new ones. Think about the way Moscow looters are replaced at first by some opportunists, then by people coming to look at what's left of their houses, and then by hordes of carpenters looking for work and slowly putting the city back to rights. That's a lot like how Natasha lets Andrei go and reconnects with Pierre, and Nikolai puts aside childish ways to take over managing his family and make things work with Marya.