The Burning of Moscow

From early on in "War and Peace" we are shown that while St. Petersburg is becoming the new thriving metropolis and social capital of Russia, Moscow remains the older and more conservative city. Older characters want to stay in Moscow while the younger characters desire to run off to the up and coming city of St. Petersburg. While St. Petersburg is young and fun, Moscow is old and boring. When the French invade Moscow in the war of 1812 the city is abandoned and left to be burned. What does the burning of Moscow symbolize? Along with the death of Old Bolkonsky, the burning of the city could represent the emergence of the younger generation as the primary figures in Russia. Perhaps the older generation has met it's end and it is time for them to take a back seat to their children. It could also symbolize the changing of culture and behavior in Russia. Maybe the burning of the city is a symbol for the loss of old customs and ways. Any thoughts on what the burning of Moscow means to "War and Peace"?