Final answer:
The capture of Moscow was catastrophic for Napoleon because the city was abandoned and set ablaze, leaving the French without vital supplies and precipitating a retreat under harsh conditions. The decimated French army faced Russian assaults, with most soldiers not surviving the return journey.
Step-by-step explanation:
The capture of Moscow by Napoleon in September 1812 was a catastrophe due to the city's abandonment and subsequent destruction the capture of Moscow was a catastrophe for Napoleon due to the city's abandonment and subsequent destruction.
After the bloody Battle of Borodino, Napoleon's forces entered Moscow, only to find it deserted and burning. The scorched earth policy by the retreating Russians left the French without supplies in a devastated landscape. As winter approached, Napoleon was compelled to order a retreat. This retreat turned disastrous as the French army, weakened by cold, starvation, and diseases like dysentery and typhus, was harassed by Russian attacks. Out of the grand army of 650,000 men, only about 100,000 survived to return to France. The failed campaign led to renewed opposition against Napoleon with Prussia and Austria joining the coalition, eventually contributing to his downfall.