Napoleon’s Russian campaign ended in failure because of the Russian weather, poor discipline and disease among the troops which was also partially due to the weather, and Napoleon’s methods. Napoleon’s methods typically focused on completely and utterly destroying his enemy as quickly as he could. This meant Napoleon’s men had to advance rapidly and live off the land until the supply wagons could catch up. When Napoleon invaded Russia, he had about 600,000 men (and 50,000 horses) and only 30 days-worth of food.
When the Russians retreated, they would burn everything behind them. As his armies marched farther into Russia, there was little food or forage for the horses. The men became weak and sick with typhus, diarrhea and dysentery which led to discipline problems. At the beginning of Napoleon’s march into Russia, the weather was too hot and at the end it was too cold