Elijah's Prophecy of Overthrow

The Hebrew verb for attack is nakah, which means to strike or smite someone. But the NIV translated that as overthrow, which was a mistake because it does not mean overthrow. So he says, you shall attack every fortified city and every choice city. And now things get really weird here. Shall fell every good tree and stop up all springs of water and ruin every good piece of land with stones. Now why is this strange? Because if you go back to Deuteronomy chapter 20, we read that if you go against a city, you shall not destroy its trees by wielding an axe against them.