Final answer:
The Russians employed a scorched-earth policy during the 1812 invasion by Napoleon's Grand Army, burning their own resources to deprive the French of supplies, leading to a disastrous retreat and ultimately contributing to Napoleon's fall.
Step-by-step explanation:
The Russians used the scorched-earth policy to defeat Napoleon’s Grand Army during the Russian campaign of 1812. As Napoleon invaded Russia with a force initially numbering 650,000 men, the Russian tactic involved retreating their forces while burning their cities, towns, and crops to prevent these resources from falling into French hands. This strategic move aimed to drain the invading army of supplies and weaken them significantly.
The approach was devastatingly effective, as it compounded Napoleon's logistical issues, already intensified by the vast distances of the Russian frontier, and meant that his army faced starvation, disease, and a brutal winter with little to no provisions. Subsequently, in the Battle of Borodino, the French and Russian armies incurred massive casualties, but the Russians continued to retreat, leaving Moscow open to French occupation. However, the city was set ablaze by the retreating Russian army upon their departure, further depriving Napoleon's forces of shelter and supplies.
As the harsh winter set in, Napoleon's retreat became a disaster, with his once-mighty Grand Army being whittled down from 650,000 to barely 100,000, many of whom were combat ineffective due to cold, hunger, and disease. Following Napoleon's failed invasion of Russia, other countries such as Prussia and Austria joined the coalition to overthrow Napoleon, signaling the beginning of the end for his hegemony in Europe.