Question

what strategy did the russian army use to devastate napoleons forces?
scorched - earth policy
trojan horse infiltration
blitzkrieg attacks

Explanation:

The scorched - earth policy involves destroying resources (such as food, infrastructure) that the enemy could use. In the context of Napoleon's invasion of Russia, the Russian army used this strategy. As Napoleon's forces advanced, the Russians retreated and burned crops, villages, etc. This left Napoleon's army without supplies in a harsh environment (especially as winter approached). The Trojan horse infiltration is a different concept (sneaking in as a friend but with hostile intent) and blitzkrieg is a fast - paced military strategy that was used in the 20th century (not in Napoleon's time).

Answer:

scorched - earth policy